U.S. DEPARTMENT OF THE INTERIOR 

U.S. GEOLOGICAL SURVEY

Marine Oxygen Isotope Stage 11 and associated Terrestrial Records:

Workshop Report

Edited by: 

Richard Z Poore1 , Lloyd Burckle2, Andre Droxler3 , and William E. McNulty1

Open-File Report 99-312

1 U.S. Geological Survey, MS 955, Natonal Center, Reston VA 21092

2 Lamont-Doherty Earth Observatory, Palisades, NewYork 10964

3 Rice University, Department of Geology and Geophysics, Houston TX 77005

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial 

standards (or with the North American Stratigraphic Code). Any use of trade, product, or firm names is for 

descriptive purposes only and does not imply endorsement by the U.S. Government.
Introduction and background

Because of the concern for potential global climate change, there is growing 

interest in better understanding and documentation of the history of natural climate and 

environmental changes. Information on recent periods of the Quaternary when conditions 

were demonstrably warmer than the present provides a way to gain insights into the likely 

impacts of possible future warming and represents one means for identifying any humaninduced diversions from natural variability. Key features include the amplitude and 

periodicity of decadal to millennial scale climate variability, the identification of systems 

and areas that are most impacted by warming, and the links between the carbon cycle and 

global temperature. The potential impact of increasing global temperature on ice caps and 

sea level is especially critical. Many glaciers and small ice caps around the world are 

receding rapidly. If larger ice sheets begin to recede, sea level could change 

dramatically. The most vulnerable ice sheet is the marine-based West Antarctic Ice Sheet, 

which contains enough water locked up as ice to raise sea level ~ 5-6 meters.

An increasing number of studies point to marine oxygen isotope stage 11 (MIS 

11) (423-362 ka) as the longest and warmest interglacial of the past 500 kyr (see Howard, 

1997 for summary). Modern barrier reef systems may have originated during or shortly 

before MIS 11, and sea level may have been substantially higher than present during MIS 

11, implying collapse of one or more major ice sheets, like the West Antarctic or 

Greenland Ice Sheets, or both. Milankovitch forcing due to changes in earth's orbital 

parameters during MIS 11 was similar to modern conditions, as were millennial-scale 

climate variations. Thus, MIS 11 is a prime candidate for an interglacial that can provide 

a credible scenario for a future global warming.

In order to better define research objectives and sampling needs for future work 

on MIS 11, a one day international workshop with over 25 participants was held in San 

Francisco on December 5, 1998. The workshop was co-sponsored by the U. S. 

Geological Survey and the Joint Oceanographic Institutions/U.S. Science Support 

Program. Five summary presentations, followed by a poster session and informal 

presentations, generated lively discussions focused on the following issues. How was 

MIS 11 generated and how long did it last? Was the earth warmer and sea level higher 

than present during MIS 11?

The agenda and list of workshop participants are in appendices 1 and 2.
Summary and Recommendations

Summary

The morning presentations were designed to summarize current information and 

identify key issues for the afternoon discussion. The talks were informal, and time was 

allowed for substantial discussion following each presentation. The topics covered 

included:

1. Stage 11 and solar forcing by Richard Muller UC Berkeley

2. The Vostok ice-core record by Dominique Raynaud LGG&E

3. The sea level record by Julie Brigham-Grette U Mass

4. The continental record of Stage 11 by Denis-Didier Rousseau U Montpellier

5. The marine record of Stage 11 by Will Howard U Tasmania

In addition to the scheduled morning presentations and poster sessions, a number 

of presentations of recent research results and activities were given at the start of the 

afternoon discussion. Abstracted summaries of workshop presentations are provided in 

the following section. In general, the workshop presentations and discussions centered 

on the following primary issues: the mechanism and length of MIS 11, the warmth of 

stage 11, and sea level during stage 11.

Origin and length of MIS 11

Although MIS 11 is one of the best developed late Pleistocene interglacial stages 

observed in the marine and terrestrial record, MIS 11 cannot be explained or modeled by 

changes in solar insolation predicted by the standard Milankovitch mechanisms as can 

most other late Pleistocene interglacial intervals (Imbrie and others, 1993; Berger and 

Jansen, 1994; Berger and others, in press). The overall depressed summer insolation 

within the 60 to 70° N latitude range during MIS 11 is too low to force the unusually 

strong interglacial conditions associated with MIS 11 and leads to what Imbrie and others 

(1993) have referred to as the "stage 11 problem". Muller presented an alternative theory
"orbital-inclination/dust" model to explain the cyclicity of Quaternary glaciations. He 

pointed out that variation in orbital inclination is a good match with the Specmap data 

(see fig. 1 of Muller this volume) and demonstrated that with his model the "stage 11 

(and stage 1) problem" disappears.

Discussion on the length of MIS 11 is linked directly to the problem of time 

scales and dating techniques. MIS 11 falls in between calibration points provided by 14C 

dating and the radiometrically dated Brunhes/Matuyama boundary. Thus the age 

estimates for MIS 11 in marine sequences are highly dependent on sediment 

accumulation rate assumptions and the use and details of "spectral tuning". Several 

versions of time scales for the Brunhes are available that can cause up to several 10's of 

thousands of years difference in the age of Termination V - the mid point of the MIS 

12/11 deglacial - and the length of the peak warm interval during early MIS 11 (e.g., 

Imbrie and others, 1984, Shackleton and others, 1990; Samthein and Tiedemann, 1990). 

Following much spirited discussion on the Milankovitch versus orbital-inclination 

mechanisms and "spectral tuning", the group concluded that the Specmap time scale 

appears to represent the best model for dating MIS 11. Using the Specmap chronology, a 

number of isotopic records, including high-accumulation rate sites in the Southern Ocean 

and North Atlantic, suggest that the peak warm interval at the beginning of MIS 11 is on 

the order of 20,000 to 30,000 years duration. This contrasts with the duration of about 

10,000 years for the warmest part of MIS 5e. The length of the climate optimum for MIS 

11 could readily explain why many older studies based on coarse sampling intervals 

found MIS 11 to be the warmest interglacial of the Bruhnes. The wide sampling intervals 

used in earlier studies were more likely to include the wannest interval of MIS 11 than 

the warmest interval of other (shorter) interglacial intervals.

Warmth of MIS 11

Lines of evidence for the degree of warming during MIS 11 from the marine, 

terrestrial, and ice-core records remain complex. The most recent isotopic and planktic 

faunal data sets from high-accumulation rate marine sequences in the north and south 

Atlantic, presented by several workshop participants, indicate that MIS 11 was not 

warmer but even slightly cooler than the Holocene (Howard, this volume; Oppo and 

others, 1998; Hodell and others, in press). In contrast, terrestrial data reviewed during the 

workshop by Rousseau indicate that stage 11 was in many instances warmer than the 

Holocene and MIS 5e. For example, the amount and composition of pollen assemblages 

in several European sections referred to the Holsteinian, which is considered to be the 

equivalent of MIS 11, indicate conditions warmer than Holocene. Similarly, pollen 

assemblages from the New Zealand contain frost-intolerant species in Holocene, MIS 5e
and MIS 11, suggesting temperatures during Stage 11 were at least as high as they were 

in Holocene and MIS 5e(Howard and others, in prep). The most recent data sets from 

numerous and diverse geochemical and isotopic analyses of the 3500 m-long ice core 

recovered at Vostock were presented by Raynaud. The ice record includes four full 

glacial-interglacial cycles characterized by strong 100 kyr (eccentricity) and 40 kyr 

(obliquity) frequencies that contrast with weak precessional frequencies. Among the four 

interglacial stages, MIS 9 and MIS 5e clearly were the wannest interglacial stages and 

have the highest CO2 and CH4 concentrations relative to MIS 7 and the Holocene. 

Raynaud was reluctant to compare these last four interglacial stages with the recorded 

interglacial MIS 11 at the base of the Vostok ice core. The MIS 11 climatic optimum 

might be not represented in the ice record, and if represented, the fluctuations of MIS 11 

T°C, CO2 and CH4 records were likely disturbed by ice flows and should be regarded 

with suspicion.

MIS 11 sea level

As summarized by Brigham-Grette, there is widespread evidence of a sea level 

high stand of about + 20 meters from extensive shoreline deposits on the north slope of 

Alaska that are correlated with MIS 11. Amino acid data and stratigraphic correlations 

indicate the age of the high stand is pre- MIS 5, but the available data do not preclude the 

high stand from being related to other Bruhnes interglacials such as MIS 9, MIS 13 or 15. 

Wave cut platforms near Sussex, UK, which suggest a +20 meters sea level, are also 

dated as Stage 11 by aminostratigraphy. The platforms fit within a regional framework 

that is very consistent with the MIS 11 assignment (Bowen, this volume). Further, 

studies in Bermuda and the Bahamas (Hearty and others, in press) support a +20 meter 

MIS 11 sea level. Raising sea level +20 meters above current levels requires elimination 

or large reductions in the West Antarctic and Greenland Ice Sheets. Scherer and others, 

(1998) have recently proposed, based on the occurrence of diatom assemblages and high 

concentrations of beryllium-10 in sediments below the West Antarctic Ice Sheet, that the 

ice sheet collapsed one or more times during the late Pleistocene, most likely during MIS 

11. The diatom assemblages are consistent with a MIS 11 correlation but slightly older 

or younger interglacials cannot be ruled out. Similarly, cosmogenic isotope 

concentrations in sediments recovered beneath the Greenland Ice Sheet are consistent 

with the elimination of the ice sheet within the past 500 kyr, and the absence of ice-rafted 

detritus during the warm peak of MIS 11 in North Atlantic OOP 980 also indicates ice 

was absent from Greenland during MIS 11 (Stanton-Frazee and others, this volume). 

Thus, different data sets from a variety of areas point towards significantly higher sea 

levels during the mid-Brunhes, between MIS 9 and 15.
Note that if a +20m sea level is accepted for MIS 11, the slightly more positive 

818O values summarized for Stage 11 at the workshop would represent cooler sea-surface 

temperatures in order to balance the more negative 818O of ocean water due to reduced 

continental ice. Thus, the combined sea level and 818O observations would indicate a 

reduction in continental ice volume took place during an interglacial that was cooler than 

the Holocene. One possible way to reconcile the sea level and 818O data would be to 

conclude that the Greenland and West Antarctic Ice Sheets became unstable and melted 

during Stage 11, because the Stage 11 temperature maxima was longer, not warmer than 

other Pleistocene interglacials.

Recommendations

Based upon the presentations and discussions at the workshop, it is evident that 

considerable gaps and uncertainties remain in our understanding of the features and 

details of the temporal and spatial variation of Earth's environment during MIS 11 and 

the other late Pleistocene interglacials. Specific research issues that require additional 

work are listed below. We find that the sea level issue is especially important. We also 

conclude that better information is needed for other late Pleistocene interglacials.

Important research goals for MIS 11 include efforts to determine the :

1. Temporal and spatial distribution, as well as magnitude of warming

2. Amplitude and frequency of millennial and submillennial-scale variability, 

especially in the first half of MIS 11

3. Global climate mosaic during one or more time intervals of stage 11

4. History of sea level change and, by extension, the fate of ice sheets in 

Greenland and Antarctica during MIS 11

5. Recovery of a complete MIS 11 ice core record

6. Impact of the establishment of modern barrier reefs on marine and 

atmospheric carbon reservoirs during MIS 11.

In the past, suggestions that DSDP and OOP consider Quaternary objectives for 

drilling have been discouraged, largely because such objectives (particularly late 

Quaternary) could be addressed with conventional piston coring. However, 

developments in climate and paleoceanographic research over the last decade and the

7
results of this workshop demonstrate that information on millenial- and submillenialscales are needed to address key questions. Recent studies (e.g., McManus and others, 

1999; Oppo and others, 1998) demonstrate that reliable climatic and oceanographic 

signals can be obtained from close sampling (2-4cm) in deep-sea sediments. Thus, high 

accumulation rate sequences and laminated deposits, such as those occurring in the Santa 

Barbara Basin and Cariaco Basin, can provide resolution comparible with ice core 

records. Even with close sampling intervals, developing millenial- and sub-millenialscale resolution requires sections that have accumulation rates in excess of -10 cm/1,000 

years. Aside from areas where overlying sediments have been removed or greatly 

compacted, sequences with >10cm 71,000 years accumulation rates beyond MIS 5 are out 

of the reach of normal piston coring. Thus, obtaining records of most late Pleistocene 

interglacial intervals with high accumulation rates requires sampling with the advanced 

piston coring or extended core barrel techniques of ODP.

Devoting entire cruises to late Pleistocene objectives may be impractical due to 

lack of sufficient high-priority targets within reasonable transit times. Developing cruises 

that combine late Pleistocene climate history objectives with other science objectives 

may be more appropriate. Outlining specific targets for coring is beyond the scope of this 

workshop report, however; following are several examples of areas that provide clear 

opportunities for multi-objective science plans.

Gulf of Mexico

Many areas of the Gulf of Mexico (GOM) preserve thick sequences of upper 

Pleistocene deposits that can provide valuable information on past climate and 

oceanographic conditions. Results from existing ODP Sites and piston cores 

demonstrate that sediments in enclosed and semi-enclosed basins on the northern and 

northwestern slopes of the GOM were deposited very rapidly and that they contain 

information on the timing and magnitude of deglacial events, fluctuations in bottom 

waters, changes in surface water faunas, and a record of volcanic activity in the Caribbean 

region (e.g., Kennett and Huddlestun, 1972; Kennett and others, 1985; Joyce and others, 

1993). Piston cores also indicate that accumulation rates >10cm/l,000 yrs persist over 

most of the western GOM. Conventional piston cores do not penetrate beyond MIS 5, 

and existing ODP HPC cores were taken early in the program and have recovery and 

disturbance problems. Additional HPC coring in the GOM will likely provide sediments 

suitable for obtaining a detailed record of most if not all of the late Pleistocene 

interglacials. These records may also provide important information on variations in the 

North American continent through sediment and fresh-water signals from the Mississippi 

and other rivers that drain into the GOM.
There is considerable interest in a GOM drilling program designed to investigate 

gas hydrate formation and processes. Proposals for one or more gas hydrate cruises are 

currently being developed. Designing a program that included gas hydrate and late 

Pleistocene climate history objectives for coring in the GOM could be an effective 

combination of science priorities that would maximize ship time and science results.

Eastern equatorial Pacific

Although accumulation rates are not as high as in the Gulf of Mexico, the 

easternmost equatorial Pacific is an important region to test hypothesis about the timing 

and extent of MIS 11 warming. It not only serves as one end of the east-west equatorial 

system and the El Nino/la Nina dance, but it also records fluctuations in the cold-water 

eastern boundary currents. Not only can stable isotopes be used to monitor time and ice 

volume, but important, widespread and easily recognizable volcanic ash layers occur in 

cores recovered from along the Central and South American coast. These may be used for 

high resolution, long distance correlation. Previous work on the Holocene in this region 

suggest that El Nino was less frequent between about 12,000 and 5,000 years BP; in 

some cases as many as 95 years elapsed between events during the Holocene while 

periodicity during the late Holocene was less than 10 years. This has implications for 

hurricane generation in the Atlantic because the jet stream during El Nino years tends to 

knock the tops off of Atlantic hurricanes before they can form.

Interestingly, MIS 5e seems also to have witnessed changes in the intensity and 

periodicity of El Nino events in the eastern equatorial Pacific. Our unpublished data 

suggests that the MIS 6/5 boundary witnessed an increase in El Nino intensity which 

lasted for a good portion of MIS 5. This raises questions about El Nino/La Nina activity 

during MIS 11 and prompts us to call for ODP sites over the location of VI9-29 and 

V19-30, (i.e., some 140 kilometers from the coast of Ecuador).

In summary, the results of this workshop point out the need for developing a longterm program to obtain high accumulation rate sequences appropriate to document and 

understand the environmental conditions and variability during OIS 11 and other late 

Pleistocene interglacials. Establishing such a program would allow ODP to contribute 

significantly to high-priority national and international global change research efforts.
References:

Berger, A., Li, S. S., and Loutre, M. F., 

in press, Modeling northern 

hemisphere ice volume over the last 

3 Ma.; Quaternary Science Reviews.

Berger, W. H., and Jansen, E., 1994, 

Mid-Pleistocene climate shift: The 

Nansen connection: AGU 

Geophysical Monograph v. 84, p. 

295-311.

Hearty, P. J., Kindler, P., Cheng, H., and 

Edwards, R. L., in press, A +20m 

middle Pleistocene sea level 

highstand (Bermuda and the 

Bahamas) due to partial collapse of 

Antarctic Ice: Geology .

Hodell, D. A., Charles, C. D., and 

Ninnemann, U. S., in press, Surface 

and deep water circulation in the 

South Atlantic sector of the Southern 

Ocean during the past 450 kyrs: 

Global and Planetary Change.

Howard, W., 1997, A warm future in the 

past: Nature v. 388, p. 418-419.

Howard, W., van der Geer, G., and 

Zahn, R., in prep, Record of marine 

and terrestrial climate of the past 1 

Ma from Site 594, Southwest 

Pacific.

Imbrie, H., Berger, A., Boyle, E., 

Clemens, S., Duffy, A., Howard, W., 

Kukla, G., Kutzbach, J., Martinson, 

D., Mclntlryre, A., Mix, A., Molfino, 

J., Morley, J., Peterson, L., Pisias, 

N., Prell, W., Raymo, M., 

Shackleton, N., and Toggweiller, J.* 

1993, On the structure and origin of 

major glaciations 2. The 100,000-

year cycles: Paleoceanography, v. 8, 

p. 699-735.

Imbrie, J., Hays, J. D., Martinson, D. G., 

Mclntyre, A., Mix, A. C., Morley, J. 

J., Pisias, N. G., Prell, W. L., and 

Shackleton, N. J., 1984, The orbital 

theory of Pleistocene climate: 

Support from a revised chronology 

of the marine 9ISO record: In 

"Milankovitch and Climate", Part 1:, 

A. L. Berger and others, eds., p. 269- 

305, Riedel, The Netherlands.

Joyce, J. E., Tjalsma, L. R. C., and 

Prutzman, J. M., 1993, North 

American glacial meltwater history 

for the past 2.3m.y.: Oxygen isotope 

evidence from the Gulf of Mexico: 

Geology (Boulder), v. 21, p. 483- 

486.

Kennett, J. P., Elmstrom, K., and 

Penrose, N., 1985, The Last 

Deglaciation in Orca Basin, Gulf of 

Mexico: High-resolution Planktic 

Foraminiferal Changes: 

Palaeogeography,

Palaeoclimatology, Palaeoecology, 

v.50,p. 189-216.

Kennett, J. P., and Huddlestun, P., 1972, 

Abrupt Climate Change at 90,000 Yr 

BP; Faunal Evidence from Gulf of 

Mexico: Quaternary Research, v. 2, 

p. 384-395.

Oppo, D. C., McManus, J. F., and 

Cullen, J. L., 1998, Abrupt climate 

events 500,000 to 340,000 years ago: 

Evidence from subpolar North 

Atlantic Sediments: Science, v. 279, 

p. 1335-1338.

10
Sarnthein, M., and Tiedemann, R., 1990, 

Younger Dyras-style cooling events 

at glacial terminations I-VI at ODP 

Site 658: Associated benthic 313C 

anomalies constrain meltwater 

hypothesis: Paleoceanography, v. 5, 

p. 1041-1055.

Shackleton, N. J., Berger, A., and 

Peltier, W. R., 1990, An alternative 

astonomical calibration of the lower

Pleistocene timescale based on ODP 

Site 677: Transactions Royal 

Society of Edinburg - Earth Science, 

v. 81, p. 251-261.

Scherer, R. P., Aldahan, A., Tulaczyk, 

W., Possnert. G., Engelhardt, H., and 

Kamb, B., 1998, Pleistocene collapse 

of the West Antarctic Ice Sheet: 

Science, v. 281, p. 82-85.

11
ABSTRACTS

+23 M STAGE 11 SEA-LEVEL IN SOUTHERN BRITIAN

-D.Q. Bowen

MARINE ISOTOPIC STAGE 11 HIGH SEA LEVEL RECORD FROM 

NORTHWEST ALASKA

-Julie Brigham-Grette

OXYGEN ISOTOPE STAGE 11 IN SOUTHERN OCEAN SEDIMENTS

-Lloyd Burckle

OXYGEN ISOTOPE STAGE 11; AN ANALOG FOR FUTURE 

CLIMATE CHANGE?

-Lloyd Burckle

MARINE ISOTOPE STAGE 11 IN THE SOUTH ATLANTIC SECTOR 

OF THE SOUTHERN OCEAN

-David A. Hodell

THE MARINE RECORD OF THE MIS 11 OSCILLATION

-W. R. Howard

DATING OF GLACIAL TERMINATION V AND DURATION 

OF THE STAGE 11 HIGHSTAND

-Daniel B. Karner, Fabrizio Marra, and Paul R. Renne

A PALEOCEANOGRAPHIC INTERPRETATION FOR A MIDDLE 

PLEISTOCENE INTERGLACIAL BASED ON MICROPALEONTOLOGY 

AND OSTRACODE MG/CA SHELL CHEMISTRY, ARCTIC COASTAL 

PLAIN, ALASKA

-D. A. Korejwo and J. Brigham-Grette

13
SOLAR FORCING AND GLACIATION

-Richard A. Muller

TROPICAL ATLANTIC PALEOCEANOGRAPHY OVER THE PAST 580 

KYRS: HIGH-RESOLUTION RECORDS FROM THE CARIACO BASIN

-Larry C. Peterson, Gerald H. Haug, Thomas F..Pedersen and Daniel M. 

Sigman

MlLLENIAL-SCALE CLIMATE VARIABILITY IN THE WESTERN 

NORTH ATLANTIC DURING MARINE ISOTOPE STAGES 11 AND 12: 

RESULTS FROM ODP LEG 172

- M.S.Poli, R. C.Thunell and D. Rio

THE VOSTOK ICE CORE IN THE CONTEXT OF STAGE 11

-D. Raynaud

THE CONTINENTAL RECORD OF STAGE 11

-Denis-Didier Rousseau

A SUBMERGED STAGE 7 TERRACE AND REEVALUATION OF THE 

LATE PLEISTOCENE STRATIGRAPHY OF OAHU, HAWAII

-C. E. Sherman, C. H. Fletcher, and K. H. Rubin

THE STAGE 11 PROBLEM AS SEEN AT ODP SITE 162-982

-C. Stanton-Frazee, D. A. Warnke, K. Venz, and D. A. Hodell

14
+23 m STAGE 11 SEA-LEVEL IN SOUTHERN

BRITAIN

D. Q. Bowen, Department of Earth Sciences, Cardiff University, Cardiff, Wales, UK,

CF1 3YE, BowenDQ@cardiff.ac.uk

Based on an assumed average uplift rate calculated from a 5e sea level at 2 m, an 

eustatic sea level for dated stage 11 marine deposits is estimated to have been at least 23 

m above present.

Two major wave-cut platforms border the English Channel from east to west in 

Sussex, UK. The higher is up to 2 km wide and ranges between ~ 20 m and an old cliff 

at -35 m that is mapped for about 40 km. The lower is up to 15 km wide and lies 

between about 2.5 m and a cliff at about 15 m that is mapped for about 50 km 

(Shephard-Thorn and others, 1982). Both platforms are overlain by fossiliferous marine 

sands and gravels. A north-south 10 km traverse between Boxgrove in the north and 

Bognor Regis in the south intersects the few fossiliferous localities that are known at 

Boxgrove, Norton, Oving, and Nyetimber (Lovell and Nancarrow, 1983).

Those localities provided samples for an aminostratigraphy that is correlated with 

an independently calibrated marine aminostratigraphic model applicable to this area 

(Bowen & Sykes, 1988), as well as one for terrestrial mollusks (Bowen and others, 1989; 

Bowen and others, in press).

Site Species D-aDe-L-Ile 

slow & moderate 

racemisers

5180

818O Highest Uplift Eustatic

mid-point dated corrected sea-level

elevation sea-level estimate

Oving

Nyetimber

Norton

Boxgrove

M. balthica

L. saxatilis

M. balthica

L. littorea

0.21 +/- 0.01 (7)

0.17 +/- 0.005 (3)

0.31+7-0.2(3)

0.28 +/- 0.2 (36)

5e

7

9

11

-

214

306.5

395.5

8.8

6

9.8

43

6

10.7

15.3

19.8

2

4.7

5.5

23.2

Table 1: Data for estimating sea-levels on a north-south 10 km transect from Boxgrove 

to Bognor Regis based on an assumption of an average uplift rate of 0.05 m/ka. D-alle/LIle data gives mean value with one standard deviation and number of samples (x). Dalle/L-Ile slow racemisers (bold) are standardised to Littorina s.l. torea; thus data for 

Boxgrove are from L. littorea, L. saxatilis and Nucella lapillus.

15
In addition, further ratios from Boxgrove were measured on Neptunia contraria 

(0.32 +/- 0.02 [3]), and a single measurement on the "moderate" epimeriser Macoma 

balthica on nearby Waterbeach, at 34.5 m, gave a ratio of 0.38. Farther east at ~ 6 m on 

the lower platform at Portslade Littorina littoralis shells provided a ratio of 0.12 +/- 

0.004 (5) that is consistent with the 5e ratio for x slow" epimerising species.

Aminostratigraphy shows that the upper platform bears marine sediments of one 

sea level, whereas the lower one was reoccupied on three occasions. It is not known if all 

three sea levels represented on the lower platform reached the cliff line at -15 m, but it is 

presumed that the oldest deposits of stage 9 were contemporaneous with it. This agrees 

with the interpretation of the British Geological Survey who suggested that the upper 

platform carried sediments of one marine transgression and regression, while the lower 

one had been re-occupied on more than one occasion (Shepard-Thorn and others, 1982). 

It does not agree with Bates and others (1997) who suggested that the deposits of three 

sea-levels occurred on the higher and two on the lower platforms.

Szabo and others (1994) estimated that global sea-level during sub-stage 5e was 

between 1 and 3 m above present. A figure of 2 m is adopted from his work to test the 

age and field relationships along the traverse from Boxgrove to Bognor Regis. Szabo and 

others (1994) further suggested that sea level was high by 130 ka as indicated by 

numerous uranium-thorium ages throughout the world.

To calculate an uplift correction graph, the sea level for sub-stage 5e is assumed 

to be 2 m. This is subtracted from the highest known elevation for the 

aminostratigraphically dated 5e deposits at Oving at 8.8 m to relate them to their 

contemporary sea level. Thus, the Oving deposits were uplifted by 6.8 m in 130 ka at an 

average uplift rate of 0.05 ka. If it is assumed that this uplift rate is capable of 

extrapolation backwards, then comparison of predicted elevations against actual ones 

may provide an estimate of contemporary eustatic sea levels (Chappell, 1974). On such 

assumption, elevations of sea-level are calculated for the midpoints of oxygen isotope 

stages 7,9 and 11 (Bassinot and others, 1994). The difference in elevation between the 

marine deposit and the uplift corrected sea-level is a measure of the height below above 

present sea-level at which it was deposited.

The uplift-corrected stage 11 sea level is 19.8 m,. Given that the highest 

Boxgrove sands are at 43 m, the contemporary eustatic sea level was at least 23.2 m 

higher than present. Thus, it is possible that substantial deglaciation of parts of West 

Antarctica and Greenland may have occurred.

References:

Bassinot, F. C, Labeyrie, L. D., Vincent, and Planetary Science Letters, v. 

E., Quidelleur, X., Shackleton, N, 126, p. 91-108. 

1994, The astronomical theory of

climate and the age of the Brunhes- Bates, M. R., Parfitt, S. A., Roberts, M. 

Matuyama magnetic reversal: Earth B., 1997, The chronology

16
palaeogeography and archaeological 

significance of the marine 

Quaternary record of the West 

Sussex coastal plain, southern 

England, U.K.: Quaternary Science 

Reviews, v. 16, p. 1227-1252.

Bowen, D. Q., Sykes, G. A., 1988, 

Correlation of marine events and 

glaciations on the Northeast Atlantic 

margin: Philosophical Transactions 

of the Royal Society of London, 

Series B: Biological Sciences, v. 

B318, p. 619-635.

Bowen, D. Q., Hughes, S., Sykes, G.A., 

Miller, Gifford EL, 1989, Land-sea 

correlations in the Pleistocene based 

on isoleucine epimerization in nonmarine molluscs: Nature (London), 

v. 340, p. 49-51.

Bowen DQ (ed), Cameron, D., 

Campbell, S., Gibbard, P.L., Holmes, 

R., Lewis, S.G., McCabe, A.M., 

Maddy, D., Preece, R.C., Sutherland, 

D.G. & Thomas, in press, Revised 

correlation of Quaternary deposits in 

the British Isles: Geological Society 

of London Special Report, v. 23. p. 

1-176

Chappell, John, 1974, Geology of coral 

terraces, Huon Peninsula, New 

Guinea: A study of Quaternary 

Tectonic movements and sea-level 

changes: Geological Society of 

America: Bulletin, v. 85, p. 553- 

570.

Lovell, J. H. , Nancarrow, P. H. A., 

1983, Sand and gravel resources; 

Chichester and Bognor, Regis, 

Sussex; No 5480, 90: Mineral 

Assessment Report, v. 138, 102 p.

Shephard-Thorn, R, Berry, F.G. & 

Wyatt, RJ., 1982, Geological notes 

and local details for 1:10 000 sheets 

SU 80 NW, NE, SW, SE; SU 90 

NW, NE, SW, SE; TQ 00 NW, SW 

(West Sussex Coastal Plain between 

Chichester and Littlehampton): 

Institute of Geological Sciences 

Keyworth, Rep. Geol. Survey.

Szabo, B. J. , Ludwig, K. R. , Muhs, D. 

R., Simmons, K. R., 1994, Thorium230 ages of corals and duration of 

the last interglacial sea-level high 

stand on Oahu, Hawaii: Science, v. 

26, p. 93-96.

17

19 Fou-ouol-
Marine Isotopic Stage 11 High Sea Level Record 

from Northwest Alaska

Julie Brigham-Grette, Department of Geosciences, University of Massachusetts,

Amherst, MA 01003-5820 USA

The northwest coast of Alaska, stretching from Nome northward to the Alaskan 

Arctic Coastal Plain and the Canadian border, contains a record of at least 6 high stands 

of sea level (see reviews in Brigham-Grette and Carter, 1992; or Kaufman and BrighamGrette, 1993). Preserved as a series of shorelines, terrace deposits, and superposed shelf 

sequences, these features contain depositional and fossil evidence of brief periods since 

the middle Pliocene when relative sea level was much higher, and climatic conditions 

were as warm or much warmer than today. Only the Gubik Formation on the Alaskan 

Arctic Coastal Plain contains all 6 high stands in superposition.

The most prominent shoreline on the northwest Alaskan coast formed during the 

Pelukian Transgression, correlated with marine isotopic stage 5e (MIS 5e). At an altitude 

of about 10-12 m, the fossil beaches, barrier islands, and spit complexes found remaining 

today represent storm beaches developed at a time when seasonal sea ice was less than 

now (Brigham-Grette and Hopkins, 1995). The next most prominent shoreline landward 

of the 5e level lies at about 22-23 m above sea level. On the Alaskan Arctic Coastal 

Plain, the shelf, beach, and lagoonal complexes deposited during this high sea stand are 

lithologically known as the Karmuk member of the Gubik Formation deposited during 

the Wainwrightian transgression (Brigham-Grette and Carter, 1992). Correlative deposits 

include the Cape Blossom Formation in the Kotzebue region (Huston and others, 1990; 

Roof, 1995) and the Anvilian transgression on the Nome Coastal Plain (Kaufman, 1992). 

Like 5e, some of these deposits are also storm beach deposits, elevated some 4 m or so 

above what may have been mean sea level.

Following several lines of evidence, local workers all consider the 22-23 m 

shoreline correlative with the MIS stage 11 interglacial high sea stand. The Karmuk 

member of the Gubik Fm is dated by U-trend dating at 540 ka +/- 60 ka (Brigham, 1985). 

An amino acid age estimate calibrated to the MIS 5e shoreline yields an age estimate of 

about 475 ka, and Pushkar (QSR, in press; Pushkar and others, in press) places the 

deposits into the middle part of the Rhizosolenia barboi diatom zone (0.43-0.36 Ma). At 

Kotzebue, the deposits are older than the Old Crow Tephra dated to 140ka (Roof, 1995), 

and on Seward Peninsula the Anvilian transgression is overlain by diamicts of the Nome 

River Glaciation bracketed by basalt flows with Ar/Ar numerical ages between 300 and 

500 ka (Kaufman and others, 1991). Following the reasoning outlined by Shackleton 

(1987), the most likely shoreline, besides the 5e interglacial, to be preserved on a 

relatively stable coast is probably MIS 11; however, we cannot entirely rule out the 

possibility that this shoreline is correlative with MIS 9, or even less likely MIS 13.

19
Other coastal areas around the world record high stands of relative sea level 

during Stage 11. For example in southern Britain, the Hoxian interglacial lies at an 

altitude of about +23 m (Bowen, this volume). Hearty (1998) reported evidence for stage 

11 oolitic limestone sequences at +20 m, in the Bahamas, while Rohling and others 

(1998) speculated that the Stage 12 sea level lowering to -140m may have been followed 

by a rise to +20 m across the sill at the southern end of the Red Sea during Stage 11. The 

Hawaiian Islands may also contain evidence of a stage 11 high sea stand, but the dating is 

poorly constrained (Chip Fletcher, personal communication., 1998).

No one has speculated about a direct connection between such a high sea level 

and the extent of ice sheets during Stage 11 because it has always been easier to dismiss 

the elevation of these features to uncertainties in regional tectonism and denudation. In 

addition, our traditional interpretation of marine isotopic evidence for Stage 11 is 

inconsistent with the demise of either the Greenland or West Antarctic Ice Sheet (WAIS) 

(Shackleton, 1987). However, the discovery by Scherer and others (1998) of middle 

Pleistocene age marine diatoms under Ice Stream B of the WAIS should compel us to 

reconsider our traditional views and the possibility of a collapse of the WAIS and maybe 

even Greenland during Stage 11. The Anvilian shoreline at Nome and the Wainwrightian 

shorelines on the Alaskan North Slope are at roughly the same elevation, yet they are in 

different tectonic regimes. For 15 years, we in northwest Alaska have been asking 

ourselves, is this just a coincidence? Or could Stage 11 have been a time of major ice 

sheet collapse unlike anything we have imagined for interglacials of the middle and late 

Quaternary. If it happened, then the climate system has more surprises for us to consider. 

Chappell (1998) pointed to the urgency of determining whether sea level was really as 

high as +20m; without question, we need to confirm 'what melted?', and if it 'could 

happen now'?

References

Bowen, D.Q., in press, +23 m Stage 11 

Sea Level in Southern Britain: This 

volume, See references there in.

Brigham, J.K., 1985, Marine 

stratigraphy and amino acid 

geochronology of the Gubik 

Formation, western Arctic Coastal 

Plain, Alaska: U.S. Geological 

Survey Open-file Report, 85-381, 

218 pg. 2 plates.

Brigham-Grette, J., and Carter, L.D. 

1992, Pliocene marine transgressions 

of northern Alaska: Circumarctic 

correlations and paleoclimatic

interpretations: Arctic, v. 45(1), p. 

74-89.

Brigham-Grette, J., and Hopkins, D.M., 

1995, Emergent-Marine record and 

Paleoclimate of the Last 

Interglaciation along the northwest 

Alaskan coast: Quaternary Research, 

v.43,p. 154-173.

Chappell, J., 1998, News and Views: 

Jive Talking: Nature, v. 394, p.ISO131.

Hearty, P.J., 1998, The Geology of 

Eleuthera Island, Bahamas, A 

Rosetta stone of Quaternary

20
stratigraphy and sea level history: 

Quaternary Science Reviews, v. 17, 

no. 4-5, p. 333-355.

Huston, M. M., Brigham-Grette, J., and 

Hopkins, D. M., 1990, 

Paleogeographic significance of 

middle Pleistocene glaciomarine 

deposits on Baldwin Peninsula, 

Northwest Alaska: Annals of 

Glaciology, v. 1, p. 111-114.

Kaufman, D. S., 1992, 

Aminostratigraphy of PliocenePleistocene high-sea level deposits, 

Nome coastal plain and adjacent 

nearshore area, Alaska: Geological 

Society of America Bulletin, v. 104, 

p. 40-52.

Kaufman, D.S., and Brigham-Grette, 

J., 1993, Aminostratigraphic 

correlations and paleotemperature 

implications, Pliocene-Pleistocene 

high sea level deposits, northwestern 

Alaska: Quaternary Science 

Reviews, v. 12, p. 21-33.

Kaufman, D.S., Walters, R.C., BrighamGrette, J., and Hopkins, D.M., 1991, 

Middle Pleistocene age of the Nome 

River Glaciation, northwestern 

Alaska: Quaternary Research, v. 36, 

p. 277-293.

Pushkar, V.S., Brigham-Grette, J., 

Cherepanov, Marina V., Hopkins, 

D.M., and Roof, S.R, in press, 

Diatom Analysis of a late Pliocene 

and Pleistocene Gubik Formation in 

the vicinity of Skull Cliff, Arctic

Alaska: Quaternary Science Reviews 

- Beringian Volume

Pushkar, V.S., Roof, S.R., Cherepanova, 

M.V., Hopkins, D.M., Ivanov, 

V.F.,and Brigham-Grette, J., in 

press, Paleogeographic and 

Paleoclimatic Significance of 

Diatoms from Middle Pleistocene 

Marine and Glaciomarine deposits 

on Baldwin Peninsula, Northwestern 

Alaska: Paleogeography, 

Paleoclimatology, Paleoecology.

Rohling, E.J., Fenton, M., Jorissen, F. J., 

Bertrand, P., Ganssen, G., and 

Caulet, J. P., 1998, Magnitudes of 

sea level lowstands of the past 

500,000 years: Nature, v. 394, p. 

162-165.

Roof, S.R., 1995, Sedimentology, 

Stratigraphy, and Paleoclimatic 

significance of middle Pleistocene 

marine, glaciomarine, and glacial 

deposits in the Kotzebue Sound 

Region, Northwestern Alaska: [Ph.D. 

dissertation], Department of 

Geosciences, University of 

Massachusetts, Amherst, 169 pg.

Scherer, R. P., Aldahan, Ala, Tulaczyk, 

Slawek , Possnert, Goran , 

Engelhardt, Hermann, Ka, 1998, 

Pleistocene collapse of the West 

Antarctic Ice Sheet: Science, v. 281, 

p. 82-85.

Shackleton, N.S., 1987, Oxygen 

isotopes, ice volume, and sea level: 

Quaternary Science Reviews: v. 6, p. 

183-190.

21
Oxygen Isotope 11 in Southern Ocean Sediments

Lloyd H. Burckle, Lamont-Doherty Earth Observatory, Palisades, New York 10964

A number of criteria were used to identify oxygen isotopes stage 11 in Southern 

Ocean deep-sea sediments: 1.) Last occurrence of the radiolarian, Stylotractus universus, 

occurs globally at the Stage 11/12 boundary. 2.) First Abundant Appearance Datum 

(FAAD) of the diatom, Hemidiscus karstenii, occurs at the Stage 11/12 boundary. 

However, there are limits to this datum; it does not occur in a continuous record well 

south to the Polar Front (PF). 3.) In the Subantarctic region, Stage 11 exhibits the highest 

calcium carbonate content of the last half million years. When combined with other 

criteria, this can be used as an aid to identifying Stage 11 cores. 4.) Oxygen isotopes. 

5.) Well to the south of the PF, Stage 11 can be recognized by counting glacial/ 

interglacial cycles. Using these criteria, more than 20 stage 11 cores have been identified 

in the Southern Ocean. To determine the average position of the Sub Antarctic Front 

(SAF), PF and Spring sea ice limit during Stage 11, percent biogenic calcium carbonate 

and opal were determined in surface (Holocene) sediments of the Southern Ocean. These 

measures in surface sediments could be used to identify the average position of the SAF, 

the PF and spring sea ice limits. This model was tested for the Last Glacial Maximum 

(LGM). Results closely agree with the CLIMAP reconstruction for the PF and the SAF 

and with Burckle and others (1982) for Spring sea ice limit. Similar data reconstruction 

for both of the PF and Spring sea ice were south of their modern locations during this 

time.

References:

Burckle, Lloyd H.,Keigwin, Lloyd D., 

Opdyke, Neil D., 1982, Middle and 

late Miocene stable isotope 

stratigraphy; correlation to the 

paleomagnetic reversal record: 

Micropaleontology, v. 28, no. 4, p. 

329-334.

23
Oxygen Isotope 11; An Analog for Future Climate

Change?

Lloyd H. Burckle, Lamont-Doherty Earth Observatory, Palisades, New York 10964

While the last interglacial (oxygen isotope substage 5e) has been considered the 

most likely analog for the future climate change, recent workers have suggested that 

oxygen isotope stage 11 may have been a better candidate. Current studies suggest that 

stage 11 was the longest and warmest interglacial of the past half million years 

compromising the stability of both the West Antarctic (WAIS) and Greenland (GIS) Ice 

Sheets. Detailed land-based studies of substage 5e and stage 11 have at least one thing in 

common: the highest sea level appears to come at the end of the interglacial. Several 

things are apparent when this observation is put within the context of the present 

interglacial: 1.) while the present interglacial has lasted for some 10,000 years, the 

drawdown of ice sheets has lasted since the end of the Last Glacial Maximum (LGM), 

and is continuing today; 2.) the level to which sea level will rise is largely dictated by the 

length of an interglacial. This appears to have been the case for oxygen isotope substage 

5e and oxygen isotope stage 11. If a long interglacial is in our immediate future then we 

face a world in which 2 of the 3 extant major ice sheets in the world may draw down and 

the sea may rise to more than 10 meters above present levels. In order to predict future 

behavior of vulnerable ice sheets, such as the WAIS and GIS, it is important to 

determine which, if any, past interglacial is the nearest analog for the present and future.

25
Marine Isotope Stage 11 in the South Atlantic 

Sector of the Southern Ocean

David A. Hodell, Department of Geology, University of Florida, Gainesville, FL

32611-7340

Marine Isotope Stage (MIS) 11 is recognized in Southern Ocean sediment cores 

by nature of its white, high-carbonate sediments at high latitude (Gersonde, Hodell and 

others, in press). Previous studies in the Southern Ocean have suggested that MIS 11 

may have been warmer than today (Howard and Prell, 1992; Hodell, 1993), prompting 

speculation that the West Antarctic Ice Sheet may have collapsed at this time (Scherer, 

1991; Scherer and others, 1998). A comparison of planktic oxygen isotopic records from 

the Atlantic sector of the Southern Ocean for peak interglacial conditions during the past 

450 kyrs revealed that MIS 11 was not substantially warmer than other interglacials at 

high southern latitudes (Hodell and others, in press). However, the duration of warm 

interglacial conditions may have been longer for MIS 11 than other interglacial stages of 

the late Pleistocene. The duration of sustained interglacial warmth was controlled by the 

eccentricity modulation of the precession cycle. MIS 11 was long in duration because 

eccentricity was low and the amplitude of the precessional cycle was damped, thereby 

resulting in fewer cold substages during the interglacial. Because the Holocene orbital 

geometry of the Earth was similar to Stage 11 (i.e., low eccentricity and reduced 

precessional amplitude), we might expect the pattern of climate change during the 

Holocene to be similar to MIS 11.

Deglaciation and sea level rise of up to 20 m above modern have been proposed 

for MIS11 (Hearty and Kindler, 1997; Bringham-Grette, this volume). During MIS11, 

global benthic 518O values were only about 0.1%o less than the Holocene and similar to 

Stage 5e. Using the standard calibration of 0.1 l%o change in 618O per 10 m of sea level 

rise (Fairbanks, 1989), a maximum of only -10 m above present would be permitted for 

MIS11. If the West Antarctic Ice Sheet (WAIS) collapsed during MIS11, then sea level 

would have risen by 5-6 m with a negligible effect on the 518O of seawater because of the 

relatively heavy oxygen isotopic composition (-20%o) of the WAIS. A 20-m rise in sea 

level during MIS 11 cannot be ruled out by the benthic oxygen isotopic record if most of 

the melted ice was relatively heavy isotopically, but 20 m of sea level rise is close to the 

limit that is permissible without a significant change in the mean 518O value of seawater.

The most distinctive feature of MIS 11 was the carbonate and carbon isotope 

chemistry of surface and deep waters in the Southern Ocean. Increased carbonate 

production occurred at high southern latitudes and decreased the ZCO2 and alkalinity of 

Antarctic surface waters. Both increased carbonate production at high southern latitudes 

and massive reef buildup during stage 11 (Droxler and others, 1997) are expected to have 

resulted in higher atmospheric pCO2 levels during MIS 11 via the polar alkalinity

27
(Broecker and Peng, 1989) and coral-reef (Berger, 1982) hypotheses, respectively. 

Evidence for higher pCO2 is lacking, however, in the long Vostok ice core record, 

although this result may not be definitive because ice at the level of Stage 11 may be 

disturbed (Raynaud and others, 1998; Raynaud, this volume). Nevertheless, planktic 

oxygen isotopic results from MIS 11 fail to indicate warming of surface waters in the 

high-latitude South Atlantic above the level of other interglacial periods as would be 

expected if pCO2 levels were elevated.

Benthic 513C values in cores bathed by Circum Polar Deep Water (CPDW) were 

greatest during MIS 11, supporting a strong input of North Atlantic Deep Water (NADW) 

to the Southern Ocean. Increased transport of NADW during MIS11 may have changed 

the chemical characteristics (decreased alkalinity and ZCO2) of CPDW, and upwelling of 

this water may have transmitted the signal to Antarctic surface waters. MIS 11 is marked 

by the highest values of planktic 813C in late Pleistocene sediment cores at high latitude in 

the South Atlantic. This may have been a consequence of increased flux of NADW 

and/or the "carbonate ion effect" (Spero and others, 1997) whereby carbonate 

precipitation south of the Polar Front lowered alkalinity and carbonate ion concentrations 

in Antarctic surface waters and resulted in higher planktic 813C values.

In summary, Stage 11 in the high-latitude South Atlantic is not remarkable in 

terms of degree of warmth compared to other interglacial stages, but rather is noted for its 

long duration and unique carbonate and carbon isotope chemistry of Antarctic surface 

and deep waters.

References:

Berger, W.H., 1982, Deglacial CO2 

buildup: constraints on the coralreef model: Palaeogeography 

Palaeoclimatololgy 

Palaeoecology, v. 40, p. 235- 

253.

Broecker, W.S., and Peng, T.H., 1989, 

The cause of glacial to 

interglacial atmospheric CO2 

change: a polar alkalinity 

hypothesis: Global 

Biogeochemical Cycles, v. 3, p. 

215-240.

Droxler, A.W., Ferro, E.G., Mucciarone, 

D.A., and Haddad, G.A., 1997, 

The marine carbonate system 

during oxygen isotope stage 11 

(423-362 ka): a case of basin-toshelf and/or basin-to-basin 

carbonate fractionation?: EOS, 

Transactions American 

Geophysical Union, v. 78, no. 

17, p. S179.

Fairbanks, R.G., 1989, A 17,000-year 

glacio-eustatic sea level record: 

Influence of glacial melting rates 

on the Younger Dryas event and 

deep ocean circulation: Nature, 

v. 342, p. 637-642.

Gersonde, R., Hodell, D., Blum, P. and 

others, in press, Proceedings of 

the Ocean Drilling Program, 

Initial Reports, 177: College 

Station, TX (Ocean Drilling 

Program).

28
Hearty, P.J., and Kindler, P., 1997, 

Direct evidence of Antarctic ice 

collapse during the middle 

Pleistocene (Stage 11?) from 

Bermuda and the Bahamas: EOS, 

Transactions. American 

Geophysical Union, v. 78, no. 

17,p.S180.

Hodell, D.A., 1993, Late Pleistocene 

paleoceanography of the South 

Atlantic sector of the Southern 

Ocean: Ocean Drilling Program 

Hole 704A: Paleoceanography, 

v. 8, p. 47-67.

Hodell, D.A., Charles, C.D., and 

Ninnemann, U.S., in press, 

Comparison of interglacial 

stages in the South Atlantic 

sector of the Southern Ocean for 

the past 450 kyrs: Implications 

for Marine Isotope Stage (MIS) 

11: Global Planetary Change.

Howard, W.R., and Prell, W.L., 1992, 

Late Quaternary surface 

circulation of the southern Indian 

Ocean and its relationship to 

orbital variations: 

Paleoceanography, v. 7, p. 79- 

117.

Raynaud, D., Barnola, J.M., Chappellaz, 

J., Delmotte, M., Lorius, C., and 

Jouzel, J., 1998, The Vostok 

greenhouse gas record: climate 

indicators and forcing: EOS, 

Transactions. American 

Geophysical Union, v. 79, no. 45, 

p. F166.

Scherer, R. P., 1991. Quaternary and 

Tertiary microfossils beneath Ice 

Stream B: Evidence for a 

dynamic West Antarctic Ice 

Sheet history: Palaeogeography. 

Palaeoclimatology. 

Palaeoecology, v. 90, p. 395-412.

Scherer, R. P., Aldahan, A. Tulaczyk, S., 

Possnert, G., Engelhardt, H., and 

Kamb, B., 1998, Pleistocene 

collapse of the West Antarctic 

ice sheet: Science, v. 281, p. 82- 

85.

Spero, H. J., Bijma, J., Lea, D. W., 

Bemis, B. E., 1997, Effect of 

seawater carbonate concentration 

on foraminiferal carbon and 

oxygen isotopes: Nature, v. 390, 

p. 497-500.

29

31
The Marine Record of the MIS 11 Oscillation

W. R. Howard, Cooperative Research Center for the Antarctic and Southern Ocean 

Environment, University of Tasmania, GPO Box 252-80, TasmainiaTOOl Australia

The Marine Isotope Stage (MIS) 11 interval (approx. 420-360 ka) has drawn 

the recent attention of the paleoclimate community because of its apparent highamplitude during an interval of relatively weak orbital .forcing due to low eccentricity. 

This anomalous behaviour presents a particular challenge to paleoclimate models 

seeking to explain the late Pleistocene record as a response to insolation forcing [e.g. 

Imbrie and others, 1993 and references therein]. The manifestations of this event in 

the marine record include a high-amplitude deglacial warming, a high-amplitude 

enrichment in benthic carbon isotopes, and sharp changes in calcium carbonate 

deposition. In addition, the chronology of the MIS 12-through-10 interval has been 

problematic because of the difficulty of extracting a distinct and unambiguous 

precession component for tuning.

The duration of MIS 11

One feature of the oxygen isotope record as compiled by the SPECMAP 

project and placed on that timescale, is that it appears to "skip" a precession cycle. 

That is, ice-volume appears to stay low longer into the interglacial than in subsequent 

interglacials. In MIS 5, for example, ice growth appears to be relatively rapid after a 

short interval of low ice volume. This unusual feature of MIS 11 raises the question: 

is the SPECMAP chronology wrong in its definition of the placement and dating of 

the end of MIS 11? Alternatively, is there a low-amplitude precession cycle 

unresolved by the records that make up the SPECMAP stack? Although a tropical 

Indian Ocean record [Bassinot and others, 1994] suggests that the latter scenario may 

be correct, the MIS 11-10 interval needs to be better defined with more records of 

appropriate resolution [e.g. Raymo, 1997; Oppo and others, 1998]. The difficulty of 

directly dating sediments in that time interval, of orbitally tuning paleoclimate 

records, and the distance from the nearest magnetic reversal, make constructing 

chronologies of the MIS 12-10 interval difficult, and make it an interval over which 

orbital time scales may be most open to revision. Magnetic intensity variations may 

provide better tuning targets, if they are phase-locked to orbits [Channel and others, 

1998].

MIS 11 as Analog for future warming?

Another point of interest is the possible "orbital analog" the MIS 11 interval 

may represent for the Holocene and near future. This similarity is due to the fact the 

earth is in a low-eccentricity geometry similar (though not identical, due to the 

relative phases of precession and obliquity) to that -400 ka, thus the possibility that 

we could look to the MIS 12-11-10 progression as a guide for what climate would do 

in the absence of any human impact. Milankovitch theory would suggest we are 

already on our way into the next glacial (leaving aside the phase of higher-frequency

31
cycles such as Dansgaard-Oeschger oscillations). But a long MIS 11, if truly an 

analog for the Holocene, would suggest longer persistence of interglacial conditions. 

Is MIS 11 really warmer than the Holocene? If so, where?

A number of studies have suggested sea-surface temperatures during MIS 11 

warmer than the Holocene [e.g Howard and Prell, 1992; Burckle, 1993], especially in 

the Southern Ocean. However recent faunal and isotopic evidence indicates that MIS 

11 may be no wanner, even slightly cooler, than the Holocene [e.g. Hodell and 

others, submitted; King and Howard, in prep.].

Indeed, the fact that neither planktonic nor benthic oxygen isotope records 

show distinct depletions requires cooler ocean temperatures, if estimates of higherthan-Holocene sea levels during MIS 11 are correct. The conditions capable of 

maintaining a combination of high sea level and cooler temperatures would be an 

interesting challenge to climate models.

Stage 12 cold or Stage 11 warmth?

One clear pattern in marine isotopic and faunal records is that MIS 12 is a 

cooler glacial than some subsequent glacial intervals; perhaps this cold glacial is what 

makes the Termination V transition so high-amplitude, and drives the perception of 

MIS 11 warmth. In this regard studies of the MIS 11 interval should cover the entire 

MIS 12-through-10 oscillation (a model for such a reconstruction may be the 

CLIMAP [1984] compilation of MIS 5 records.)

Geochemical anomalies

MIS 11 appears as a prolonged maximum in calcite burial in the subpolar 

Atlantic and Indian Oceans [e.g. Howard and Prell, 1994], with maxima in carbonate 

dissolution in the Pacific [Peterson and Prelll985; Farrell and Prell, 1989]. The burial 

maxima in the Atlantic and Southern Oceans appear to be driven partly by deep-water 

preservation, possibly a result of enhanced northern source water input [Oppo and 

others, 1990]. (However MIS 11 does not show up as a benthic carbon isotope 

maximum in all records; see for example Curry [1996]).

To the extent that the MIS 11 calcite maximum represents production, it may 

correspond to warming of polar/subpolar oceans, with increased areas within the SST 

range of nannofossil calcite production. The calcite reservoirs laid down at this time 

may be part of explanation for the Equatorial Pacific and Indian Ocean dissolution, 

and would represent ecological forcing of geochemical change in addition to sea-level 

forcing [Opdyke and Walker, 1992].

32
Priorities for future MIS 11 studies should include:

 Relative timing of paleoclimate change through this interval 

(interhemispheric, SST vs. ice volume) in higher-resolution records

 More complete accounting for the oceanic carbonate budget, 

especially deep-basin burial rates

 A global reconstruction of SST

 Refinement of chronology

References:

Bassinot, F., Labeyrie, L. D., Vincent, 

E., Quidelleur, X., Shackleton, 

N. J. & Lancelot, Y., 1994, The 

astronomical theory of climate 

and the age of the BrunhesMatuyama magnetic reversal: 

Earth Planet Science Letters, v. 

126, p. 91-108.

Burckle, L. H. (1993) Late Quaternary 

interglacial stages warmer than 

present: Quaternary Science 

Revews, v. 2, p. 825-831.

Channell, J. E. T., Hodell, D. A., 

McManus, J. and Lehman, B., 

1998, Orbital modulation of the 

Earth's magnetic field intensity: 

Nature, v. 394, p. 464-468.

CLIMAP. ,1984, The last interglacial 

ocean: Quaternary Research, v. 

21, p. 123-224.

Curry, W. B., 1996, Late Quaternary 

deep circulation in the western 

Equatorial Atlantic: In: The 

South Atlantic: Present and Past 

Circulation (Ed. by G. Wefer, W. 

Berger and G. Webb), pp. 577- 

598.

Howard, W. R. and Prell, W. L., 1992, 

Late Quaternary surface 

circulation of the Southern Indian 

Ocean and its relationship to 

orbital variations: 

Paleoceanography, v. 7, p. 79- 

118.

Howard, W. R. & Prell, W. L., 1994, 

Late Quaternary carbonate 

production and preservation in 

the Southern Ocean: Implications 

for oceanic and atmospheric 

carbon cycling: 

Paleoceanography, v. 9, p. 453- 

482.

Imbrie, J., Boyle, E. A., Clemens, S. 

C, Duffy, A. C, Howard, W. R., 

Kukla, G., Kutzbach, J., 

Martinson, D. G., Mclntyre, A., 

Mix, A. C., Molfino, B., Morley, 

J. J., Peterson, L. C., Pisias, N. 

G., Prell, W. L., Raymo, M. E., 

Shackleton, N. J. & Toggweiler, 

J. R., 1993, On the structure and 

origin of major glaciation cycles. 

2. The 100,000-year cycle: 

Paleoceanography, v. 8, p. 699- 

735.

33
Opdyke, B. N. & Walker, J. C. G., 

1992, Return of the coral reef 

hypothesis: Basin to shelf 

partitioning of CaCO3 and its

effect on atmospheric CO2 : 

Geology, v. 20, p. 733-736.

Oppo, D. W., Fairbanks, R. G., 

Gordon, A. L. & Shackleton, N. 

J., 1990, Late Pleistocene 

Southern Ocean 813C variability: 

Paleoceanography, v. 5, p. 43-54.

Oppo, D. W., McManus, J. F. & 

Cullen, J. L., 1998, Abrupt 

climate events 500,000 to 

340,000 years ago: Evidence 

from subpolar North Atlantic 

sediments: Science, v. 279, p. 

1335-1338.

Peterson, L. C. & Prell, W. L., 1985, 

Carbonate preservation and rates 

of climatic change: An 800 kyr 

record from the Indian Ocean: 

In: The Carbon Cycle and 

Atmospheric CO2 : Natural

Variations Archean to Present: 

(Ed. by E. Sundquist and W. S. 

Broecker), AGU, Washington, 

D^C. Geophysical Monograph, v. 

32, pp. 251-269.

Raymo, M. E., 1997, The timing of 

major climate terminations: 

Paleoceanography, v. 12, p. 577- 

585.

34
40Ar/39Ar dating of Glacial Termination V and duration of the

Stage 11 highstand

Daniel B. Karner, Department of Physics, University of California, Berkeley,

CA 94720, USA

Fabrizio Marra, Istituto Nazionale di Geofisica, Via di Vigna Murata 605, 00143 Rome,

Italy

Paul R. Renne, Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 

94709, USA, and Dept. of Geology and Geophysics, University of California, Berkeley,

California 94720, USA

Assigning ages to geologic events is of fundamental importance to the earth 

sciences. While there are many radioisotopic and non-radioisotopic methods being 

employed to date climate change events, the accuracy and temporal resolution of most 

non-radioisotopic methods is insufficient to answer questions such as the timing and 

duration of glacial or interglacial cycles. One exception to this is the method of tuning 

climate proxies in sediment to Earth's orbital parameters. While details of the tuning 

procedure are in some respects still controversial (e.g. Muller and MacDonald, 1997, and 

references therein), a growing number of direct comparisons between radioisotopic vs. 

orbitally tuned chronologies suggests that tuning can be fairly accurate through the last 

million years. However, the predicted timing of discrete events may vary by 10 kyr or 

more when different orbital tuning targets are used (e.g. Berger and others, 1993 vs. 

1995).

Radioisotopic dating systems based on 238U and 40K decay provide the most 

accurate and precise age constraints for events that have occurred from 0.1-1.0 Ma. Useries methods have been used extensively to date coral reefs, which grow near sea level, 

and have provided good age constraint for the Stage 5 and (to a lesser extent) Stage 7 sealevel highstands. However, U-series methods have not provided reliable ages for older 

highstand deposits, such as Stage 11, the focus of this work. The 40Ar/39Ar method, on 

the other hand, can be used to date reliably all of the Pleistocene highstand deposits, 

including those from Stage 11 (e.g. Karner and Renne, 1998).

We have used the ^Ar/^Ar method to date volcanic ash layers intercalated with 

coastal sediments in the Tiber River Valley and Delta (Karner and Renne, 1998; Karner 

and Marra, 1998). Using the Pleistocene-Holocene transition as an analogue for past 

glacial terminations, we interpret the onset of significant (10s of meters) alluviation in the 

Tiber River Valley and Delta to occur at, or shortly following, glacial terminations, 

analogous to the buildup of coral reef material on carbonate-dominated ocean margins. A 

detailed discussion of the Tiber River and Delta alluvial deposits and their relationship to 

sea-level variations is given by Karner and Marra (1998).

35
Figure 1.

Ponte Galeria 

(Fosso Galeria Valley)

Rome 

(Tiber River Valley)

Pliocene-Pleistocene Substrate

Pliocene-Pleistocene Substrate

-20-J Eolian sand Fluvial or marine gravel

Figure 1 is a composite stratigraphic column of alluvial sections around Rome, 

corresponding to the Holocene plus eight previous interglacials. Tephra ages relevant to 

Stage 11 are from Karner and Renne (1998), plus one added ^Ar/^Ar age of 406 ± 3 ka 

(2_ analytical precision, Karner and others, in press.) on sanidine from a pumice horizon. 

This pumice is the uppermost airfall horizon identified so far in the Stage 11 section, and 

therefore can be used to approximate the end of the Stage 11 sea-level highstand.

Ages of ash layers that stratigraphically bracket the start of aggradation can be 

used to estimate the timing of the glacial termination. This termination age can then be 

compared with termination ages from other dating methods, so long as all systematic 

errors inherent to each method are propagated into their age errors. From the Rome 

section, Glacial Termination V, which led to the start of Stage 11, was determined to 

occur within the interval 416-448 ka (95% confidence interval, including 40Ar/39Ar 

systematic errors, Karner and Renne, 1998). This can be compared to orbitally tuned 

deep-sea sediment records for agreement (Figure 2). Imbrie and others (1984) 

determined the age of Termination V in the SPECMAP record to be 423 ± 5 ka, whereas 

Shackleton and others (1990) determined the age to be 416 ka at ODP Site 677 (no error 

reported). While the SPECMAP record falls well within the 95% confidence interval of 

the ^Ar/^Ar ages, the Site 677 record is at the extreme limit of the 95% confidence 

interval, and may therefore be suspect.

36
Figure 2.

CD 

^

O

CO 

H

CO 

CD

CD 

CC

TV95%CI = 416-448ka 

(Rome secton)

D)

±

CD

CO 

CD 

CO

.1 jc

CD

CC

o

0.5

There are additional timing considerations with the Rome and Site 677 records. 

No time lag is assumed between the termination and the resumption of coastal 

sedimentation, and therefore the true age of the termination should be somewhat older 

than predicted from the Rome sections. Additionally, the age uncertainty of the Site 677 

record is not given by Shackleton and others (1990), but is probably at least that of the 

sample spacing, about 2-5 kyr for Stage 11. These additional errors do not bring the two 

records into better agreement, however, because, at best, they would pull each time scale 

in the same direction. At worst, the Rome section could be pulled in the older direction 

and Site 677 in the younger direction, at which point the two records would disagree at 

the >95% confidence level. Based on our comparison with the SPECMAP and Site 677 

time scales, we suggest that the SPECMAP chronology is more accurate than that of Site 

677 for the timing of Termination V.

37
Figure 3.

1_ 

CD

ooo 

CO

> * 

JO 

CD

DC

2

follows 

aggradation

minimum duration 

= 15 kyr. 

I I

0.38

Site 677

maximum duration = 41 kyr.

precedes aggradation

0.4 0.42 0.44 0.46 0.48

Age (ka)

0) 

-H

CD 

JCD

CO 

CD 

(0

0) 

' £5

jcg

CD DC

0.5

The duration of the Stage 11 highstand (Figure 3) can be assessed from the Rome 

section ^Ar/^Ar ages without inclusion of systematic errors, since the ^Ar/^Ar ages are 

all calibrated against the same standard and therefore would all be shifted in the same 

direction by a systematic error. The minimum duration of aggradation in the Rome 

section can be calculated using the broadest range of ages from airfall horizons within the 

aggradational section. The oldest airfall tephra age determined in the Stage 11 section is 

427 ± 5 ka, and the youngest is 406 ± 3 ka (2_). Therefore, a minimum duration of 15 

kyr (427-406 = 21 kyr - 6 kyr for errors added in quadrature) can be assigned to the 

Stage 11 alluvial section. The maximum duration of the Stage 11 alluvial section can be 

assessed using the youngest age from volcanic material reworked in the base of the 

alluvial section (434 ± 8 ka), and the oldest age from volcanic material unconformably 

above the alluvial section (404 ± 7 ka). These ages provide a maximum duration of 41 

kyr (434-404 = 30 kyr + 11 kyr for errors added in quadrature) for Stage 11 alluviation. 

Since a large portion (17 kyr) of this 15-41 kyr (95% confidence) duration interval is due

38
to analytical errors associated with the ^Ar/^Ar ages, additional analyses could reduce 

the analytical error contribution.

A recent discussion of the last four interglacials by Winograd and others (1997) 

suggests that contrary to the long-held view that interglacials last about 10 kyr, 

continental sections dated by means other than orbital tuning suggest that their durations 

were closer to 20 kyr. The present work supports this observation for Stage 11, with a 

minimum duration of 15 kyr and maximum duration of 41 kyr at 95% confidence. With 

additional 40Ar/39Ar analyses on the key ash layers, the Rome sections may be able to 

answer the question of whether the Stage 11 highstand lasted for 20 kyr (as suggested by 

Winograd and others, 1997) or whether it was anomalously long (e.g. 29 kyr) as 

suggested by Sarnthein and Tiedemann (1990).

References

Berger, W.H., Bickert, T., Schmidt, H., 

and Wefer, T., 1993, Quaternary 

oxygen isotope record of pelagic 

foraminifers; Site 806, Ontong Java 

Plateau: Proceedings of the Ocean 

Drilling Program, Scientific Results, 

v. 130, p. 381-395.

Berger, W.H., Bickert, T., Wefer, G., 

and Yasuda, M.I., 1995, BrunhesMatuyama boundary; 790 k.y. date 

consistent with ODP Leg 130 

oxygen isotope records based on fit 

to Milankovitch template: 

Geophysical Research Letters, v. 22, 

no. 12, p. 1525-1528.

Imbrie, J., Hays, J.D., Martinson, D.G., 

Mclntyre, A., Mix, A.C., Morley, 

J.J., Pisias, N.G., Prell, W.L., and 

Shackleton, N.J., 1984, The orbital 

theory of Pleistocene climate: 

support from a revised chronology of 

the marine 318O record, in Berger, 

A., and others, eds., Milankovitch 

and Climate, Part 1: Higham, MA, 

D. Reidel Publishing Company, p. 

269-305.

Karner, D. B., and Marra, F., 1998, 

Correlation of fluviodeltaic

aggradational sections with glacial 

climate history: A revision of the 

Pleistocene stratigraphy of Rome: 

Geological Society of America 

Bulletin: v. 110, no. 6, p. 748-758.

Karner, D. B., and Renne, P. R., 1998, 

40Ar/39Ar geochronology of Roman 

Volcanic Province tephra in the 

Tiber River valley: Age calibration 

of Middle Pleistocene sea-level 

changes: Geological Society of 

America Bulletin, v. 110, no. 6, p. 

740-747.

Karner, D. B., Marra, F., and Renne, P. 

R., in press, Tectonic control on 

volcanism in the Roman Volcanic 

Province.

Muller, R.A., and MacDonald, G.J., 

1997, Glacial cycles and 

astronomical forcing: Science, v. 

277, p. 215-218.

Sarnthein, M., and Tiedemann, R., 1990, 

Younger Dryas-style cooling events 

at Glacial Terminations I-VI at ODP 

Site 658: associated benthic 313C 

anomalies constrain meltwater

39
hypothesis: Paleoceanography, v. 5, of the Royal Society of Edinburgh -

no. 6, p. 1041-1055. Earth Sciences, v. 81, p. 251-261.

Shackleton, N. J., Nicholas J. , Berger, Winograd, I. L, Landwehr, J. M.,

A. , and Peltier, W. A., 1990, An Ludwig, K. R., Coplen, T. B., and

alternative astronomical calibration Riggs, A. C., 1997, Duration and

of the lower Pleistocene timescale structure of the past four

based on ODP Site 677: Transactions interglaciations: Quaternary

	Research, v. 48, p. 141-154.

40
A Paleoceanographic Interpretation for a Middle

Pleistocene Interglacial Based on Micropaleontology

and Ostracode Mg/Ca Shell Chemistry, Arctic Coastal

Plain, Alaska

D A Korejwo ; J Brigham-Grette, University of Massachusetts, Department of Geosciences,

Amherst, MA 01003

Introduction

Marine and terrestrial records spanning the past 500 ka indicate that oxygen isotope stage 

11 (423-362 ka) was one of the warmest interglacials on record, resulting in high global sea levels 

and temperatures possibly even warmer than present (i.e. Zhongli and others, 1991; Rousseau and 

others, 1992; Burckle, 1993; Hodell, 1993; Ortiieb and others, 1996). The Karmuk Member of 

the Gubik Formation, Arctic Coastal Plain, Alaska, is composed of middle Pleistocene 

transgressive marine sediments deposited up to 22 m above present sea level, suggesting 

deposition during an unusually high sea level event. Currently, the best estimates suggest a 

depositional age for the Karmuk Member corresponding to stage 11 (Kaufman and others, 1991; 

Kaufman and Brigham-Grette, 1993). This study will establish a temperature estimate for the 

stage 11 interglacial based on comparisons between marine ostracode assemblages and ostracode 

Mg/Ca shell chemistry, thus documenting a high latitude northern hemispheric record for one of 

the warmest periods in Earth's history.

Figure 1. Study area at Skull Cliff, northern Alaska. Skull Cliff extends 80 

km between Barrow and Peard Bay

41
The Gubik Formation consists of a series of Pliocene to Pleistocene-aged marine 

transgressive sequences which record late Cenozoic high sea-level events (Brigham, 1985). These 

transgressive sequences comprise most of the exposed sediments along Skull Cliff, which extend 

80 km between Barrow and Peard Bay (Figure 1). The Karmuk Member of the Gubik Formation 

represents one of the Pleistocene transgressive units. This sequence was deposited during the 

Wainwrightian transgression, when relative sea-level was 23 m above present level and marine 

conditions are thought to be similar to modern conditions (Kaufman and Brigham-Grette, 1993).

Materials and Methods

Materials used in this study were collected from exposed gullies along Skull Cliff. 

Sediment was collected from three sampling localities at 10 cm intervals. The most complete 

section yielded 700 cm of sediment and may represent an entire transgressive sequence consisting 

of offshore (a lower marine mud unit), nearshore (an interbedded fine sands and mud unit), and 

beach (a medium to coarse pebbly sand unit) deposits.

Paleontology

A total of 26 ostracode taxa were identified from 50 intervals. Four species dominate 

Karmuk sediments with a combined average relative abundance of 91%. The four dominant 

species are Paracyprideis pseudopunctiallata, Normanicythere leioderma, Rabilimis 

septentrionalis, and Sarsicytheridea bradii. Both dominant and diagnostic taxa have been selected 

for qualitative and quantitative taxonomic analysis.

Paleontological associations yield paleoenvironmental inferences. Euryhaline and 

eurythermal taxa present include R. septentrionalis, P. pseudopunctillata, Loxoconcha 

venepidermoidea and indicate very shallow, nearshore conditions. Other species which prefer 

more stable salinity and temperature conditions are found in deeper, offshore environments and 

include N. leioderma and Robertsonites tuberculata.

Mg/Ca Shell Chemistry

The Mg/Ca ratio in ostracode shell calcite is used in deep sea studies as a paleotemperature 

proxy based on the temperature-dependent uptake of Mg into the shell calcite. For this study, trace 

elements were analyzed on specimens of P. pseudopunctillata. Preliminary results indicate that the 

marine paleoenvironment during Karmuk deposition was relatively stable. There is a general trend 

toward decreasing Mg/Ca values during sediment deposition punctuated by fluctuations within the 

Mg/Ca record. Comparisons to modern shell chemistry analyses will be used in order to address 

the significance of the fluctuations seen in the fossil chemistry record, as well as in assessing a 

paleotemperature history (i.e. Dwyer and others, 1995; Cronin and others, 1996; Ingram, 1998).

Conclusions and Future Work

Paleoenvironmental inferences obtained from both qualitative and quantitative analyses of 

microfaunal assemblages suggest that deposition of the Karmuk Member occurred in middle to 

inner neritic water depths. Fossil ostracode assemblages indicate that stage 11 conditions were 

similar to present marine conditions. The ostracode assemblages are dominated by normal marine, 

frigid to cold temperate species indicating fairly stable temperature and salinity conditions.

Decreasing Mg/Ca ratios from the paleotemperature-inferred ostracode shell chemistry 

record suggest a gradual decline in water temperature over time, possibly indicating a climatic 

deterioration from optimum interglacial conditions. Fluctuations in the Mg/Ca record likely record 

fluctuations in the paleoenvironment and remain to be assessed for their significance.

42
These preliminary results document an extremely warm interglacial in northern Alaska 

characterized by a sea level up to 22 m above present. The current findings will be supplemented 

by further investigation of species associations. Additionally, the shell chemistry results will be 

compared to modem chemistry data with the goal of quantifying significant temperature changes. 

By establishing a marine paleotemperature estimate in northern Alaska for stage 11, we hope to add 

to the understanding of the global sea level record for one of the warmest periods in Earth's recent 

history.

References

Brigham, J.K., 1985, Marine stratigraphy 

and amino acid geochronology of the 

Gubik Formation, western Arctic Coastal 

Plain, Alaska: U.S. Geological Survey, 

Open-File Report 85-381, 218 pp.

Burckle, L., 1993, Late Quaternary 

interglacial stages warmer than present: 

Quaternary Science Reviews, v.12, p. 

825-831.

Cronin, T.M., Dwyer, G.S., Baker, P.A., 

Rodriguez-Lazara, J., and Briggs Jr., 

W.M., 1996, Deep-sea ostracode shell 

chemistry (Mg:Ca) ratios and late 

Quaternary Arctic Ocean history: In 

Andrews, J.T., Austin, W.E.N.

Bergsten, H. and Jennings, A.E. (eds), Late 

Quaternary Palaeoceanography of the 

North Atlantic Margins: Geological 

Society Special Publication, no. Ill, pp. 

117-134.

Dwyer, G.S., Cronin, T.M., Baker, P.A., 

Raymo, M.E., Buzas, J.S. and Correge, 

T., 1995, North Atlantic deep-water 

temperature change during late Pliocene 

and late Quaternary climatic cycles: new 

insight from ostracode shell chemistry: 

Science, v. 270, p. 1347-1351.

Hodell, D.A., 1993, Late Pleistocene 

paleoceanography of the south Atlantic 

sector of the Southern Ocean: Ocean 

Drilling Program Hole 704A: 

Paleoceanogrpahy, v. 8, p. 47-67.

Ingram, C., 1998, Palaeoecology and 

geochemistry of shallow marine

Ostracoda from the Sand Hole 

Formation, Inner Silver Pit, southern 

North Sea: Quaternary Science Reviews, 

v. 17, p. 913-929.

Kaufman, D.S. and Brigham-Grette, J., 

1993, Aminostratigraphic correlations 

and paleotemperature implications, 

Pliocene-Pleistocene high-sea-level 

deposits, northwestern Alaska: 

Quaternary Science Reviews, v. 12, p. 

21-34.

Kaufman, D.S., Walter, R.C., BrighamGrette, J. and Hopkins, D.M., 1991, 

Middle Pleistocene age of the Nome 

River Glaciation, northwestern Alaska: 

Quaternary Research, v. 36, p. 277-293.

Ortlieb, L., Diaz, A., and Guzman, N., 

1996, A warm interglacial episode during 

oxygen isotope stage 11 in northern 

Chile: Quaternary Science Reviews, v. 

15, p. 857-871.

Rousseau, D-D., Puissegur, J-J. and 

Lecolle, F., 1992, West-European 

molluscs assemblages of isotopic stage 

11 (middle Pleistocene): climatic 

implications: Palaeogeography, 

Palaeoclimatology, Palaeoecology, 92, 

15-29.

Zhongli, D., Rutter, N., Tungsheng, L., 

Evans, M.E., and Yuchun, W., 1991, 

Climatic correlation between Chinese 

loess and deep sea cores: a structural 

approach. In Tungsheng, L. (ed), Loess, 

Environment and Change, The Series of 

the XIH INQUA Congress, p. 168-186.

43
Solar Forcing and Glaciation

Richard A. Muller, University of California Berkeley, California 94720

In the early-to-mid 1980's, there appeared to be strong indications that the CrollMilankovitch insolation theory of glacial cycles had been confirmed. Spectral analysis of 

ice volume proxy data showed cycles with periods near 100 kyr, 41 kyr, and 23 kyr, good 

matches to the frequencies that appear the insolation model. Although there were 

remaining difficulties, many researchers considered it virtually inconceivable that the 

theory could be fundamentally wrong. Since then, for a decade and a half, many scientists 

have not only accepted the theory, but they have built it into the analysis of their data. 

Insolation forcing is used to tune the time scale of deep sea sediment data, in an attempt to 

try to remove the effects of varying sedimentation rates.

However, the problems that remained have not found entirely satisfactory 

solutions. Several of the most problematic features of the data are (a) the dominance of 

the 100 kyr cycle, (b) the weakness of the 23 precession kyr cycle, (c) the presence of 

strong modulation in the glacial cycles at stages 1 and 11, when the insolation modulation 

is very weak, (d) the absence of the expected strong 400 kyr insolation cycle in ice 

volume proxy data, and (e) a causality problem: Data at a site known as Devil's Hole 

indicate that glacial terminations sometimes precede the rise in insolation that is supposed 

to have caused it (Winograd and others, 1992).. Most of these problems have been 

discussed in detail by Imbrie and others(1992, 1993).

Many modifications of the insolation model have been proposed to address the 

problems. The nonlinear ice model of Imbrie and Imbrie (1980) is one of the most 

successful. It provides a mechanism for an enhanced 100 kyr cycle by attributing it to the 

envelope of the precession cycle. Virtually any nonlinear mechanism operating on 

precession will provide this effect since the precession parameter literally is a product of 

the eccentricity (which has a quasi-100 kyr cycle) and the true precession. But, by itself, 

the nonlinear ice model leaves a 100 kyr cycle that is weaker than the 23 kyr cycle, 

whereas in fact the 100 kyr cycle is dominant and the observed 23 kyr cycle so weak that 

in the ice-proxy data it verges on non-presence. To try to address these problems, it is 

common to assume an ad-hoc amplifier that enhances the 100-kyr signal, and to invoke 

"chatter" in the sedimentation rate to suppress a 23 kyr signal. And an additional 

suppressor must be hypothesized to account for the absence of the 400 kyr cycle. The 

causality problem has been addressed by disputing the interpretation of the Devil's hole 

data. However recent measurements of sea levels recorded in corals have confirmed the 

Devil's Hole results (Esat and others, 1999).

Rather than see if we can add enough parameters to the old model to make it fit the 

data, it is a worthwhile exercise to ask what conclusion paleoclimatologists might reach 

today, if they weren't already deeply committed to the Milankovitch mechanism. A

45
second orbital cycle, inclination, has been discovered (Muller 1994, Muller and 

MacDonald, 1995) that matches the 100 kyr cycle of the ice ages, so we even have an 

alternative to eccentricity to consider for this dominant cycle. Figure 1 shows the best fits 

of these two models to the data. Orbital inclination provides a much better fit than does 

eccentricity.

Excellent new data are now available. We know, for example, that at Sites 607 

and 677, an extremely strong 41 kyr cycle is present during the period from 1 to 2.5 Ma, 

and that this signal is evident in spectral analysis even when no tuning is applied to the 

sedimentation rate (Muller and MacDonald, 1997). The strength of this signal implies that 

the sedimentation rate has been constant on the 41 kyr time scale; the 41 kyr period is 

close enough to that of precession that it makes chatter in sedimentation an unlikely 

explanation for the absence of the 23 kyr precession cycle.

In addition, there is compelling evidence for relatively constant sedimentation at 

Site 806 in the Western Pacific for the last 800 kyr (Muller and MacDonald 1997). This 

fact allows one to look for fine structure expected from the insolation model. In 

particular, it is well known (Berger, 1978; Quinn and others, 1991) that the "100 kyr" 

peak in eccentricity is actually a split peak, consisting of two components, with periods 95 

kyr and 125 kyr. Yet spectral analysis shows that the expected splitting is absent, in 

contradiction to every published insolation-based theory known to the present author. 

This is evident in the data shown in Fig. 2. The spectrum does provide a good match to 

that of the new orbital inclination parameter. To salvage the Milankovitch theory, one 

must now invoke a mechanism that somehow suppresses the 125 kyr peak, while 

enhancing the 95 kyr one. Such fine tuning ability is absent in virtually all geologic 

processes that have previously been considered. For example, the spectrum of the 

nonlinear ice model has a strong split peak, shown in Fig. 2(d), in disagreement with the 

data Fig. 2 (a) and (b).

The link of orbital inclination to the 100-kyr glacial cycle was first suggested by 

Muller and MacDonald (Muller, 1994; Muller and MacDonald, 1997). In these papers, we 

proposed that the coupling mechanism could be accretion of interplanetary dust, although 

we were unwilling (and unable) to predict whether the dust would cause the ice to grow or 

decline. This model has been criticized for the lack of a detailed mechanism, although we 

respond by pointing out the ad-hoc nature of the models that are used in the Milankovitch 

theory. If we are allowed to be equally ad-hoc, then we too can find mechanisms. For 

example, we hypothesize that accreting dust affects the ozone concentration in the midstratosphere. It can do this through several mechanisms: the delivery of significant 

bromine (known to be enhanced in such dust; see Flynn (Flynn and others, 1993; Flynn, 

1994), and by providing solid surfaces for heterogeneous chemistry (similar to the 

surfaces that are known to be important in the Antarctic Ozone hole creation). The ozone 

variations cause changes in the height of the tropopause (the presence of ozone is what 

creates the tropopause), which in turn affects the global circulation patterns and the 

latitudinal transport of water vapor to the northern glaciers. All these phenomena can be 

summarized by one adjustable parameter, which we use to fit the amplitude of Fig. 1.

46
(A) inclination & Specmap

0 800

(B) eccentricity & Specmap

200 400 600 

age (ky)

800

Figure 1. Best fits of global ice proxy data (Specmap) to two orbital parameters: (A) orbital 

inclination (smooth curve) plotted over the Specmap data; (B) eccentricity (smooth curve) 

plotted over the Specmap data. Each fit has two parameters: amplitude and time lag. Orbital 

inclination accounts for 49% of the variance of the data; eccentricity accounts for 15%. If 

the fits are done simultaneously, inclination accounts for 49% and eccentricity for less than 

2%. The Stage-1 and Stage-11 problems are evident in the poor agreement near 0 and 400 ky 

for the eccentricity fit; there is no similar problem in the inclination fit.

47
25

20

15

10

5

0

120

100

80

60

40

20

0

(b) ' 

SPECMAP0.005 0.01 0.015 

frequency (cycles/kyr)

0.02

Figure 2. Spectral fingerprints of two 818O data sets and three models. Both the data and the 

models cover the ages 0 to 600 ka. The frequency scale has been expanded to facilitate 

comparison of peak shapes near 0.01 cycles/kyr (period 100 kyr). All the data show a similar 

pattern: a single narrow peak near frequency f = 0.01 cycles/kyr (period 100 kyr), in good 

agreement with the orbital inclination theory, and in disagreement with the complex spectra 

predicted by the eccentricity and nonlinear ice theories.

48
Thus, with one parameter, this model can account for the observed relationship between 

orbital inclination and global ice. We don't claim this is an adequate model; we only 

claim that it is no more ad hoc than the models used in the Milankovitch approach, and 

therefore equally deserving of serious consideration.

We speculate that if the data we have today were available in 1985, and if it had 

been known that the orbital inclination of the earth was a better match to that data, that the 

adoption of the Milankovitch theory as the standard model would not have proceeded at 

that time. With the orbital inclination model, there is no stage-11 problem, no stage-1 

problem, no causality problem, no 400 kyr problem, and no mystery about the small 

amplitude of the 23 kyr cycle. The inclination model even has a natural explanation for the 

sudden appearance of the 100 kyr cycle at about 1 Ma, since solar system dust is known to 

have gone a sudden increase at that time (Parley, 1995). Indeed, if this were all known in 

1985, it is possible that the orbital-inclination/dust theory might itself have been 

prematurely adopted as the standard model.

References

Berger, A., 1978, Long-term variation of 

daily insolation and Quaternary 

climatic changes: Journal of the 

Atmospheric Sciences, v. 35, p 

2362-2367.

Esat, T.M., McCulloch, M.T., Chappell, 

J., Pillans B., and Omura, A., 1999, 

Rapid Fluctuations in Sea Level 

Recorded at Huon Peninsula During 

the Penultimate Deglaciation: 

Science, v. 283, p 197-201.

Parley, K., 1995, A 70 Million Year 

Record of Extraterrestrial Helium 

Fallout to the Deep Sea: Nature, v. 

378, p 153-156.

Flynn, G.J., 1994, Interplanetary dust 

particles collected from the 

stratosphere: physical, chemical, and 

mineralogical properties and 

implications for their sources: 

Planetary and Space Science, v. 42, p 

1151-1161

Flynn, G.J., Sutton, S.R., Bajt, S., Klock, 

W., Thomas, K.L., and Keller L.P., 

1993, The Volatile Content of 

Anhydrous Interplanetary Dust: 

Meteoritics, v. 28, no. 3, p 349.

Imbrie, J., Boyle, E.A., Clemens, S.C., 

Kutzback, J., Martinson, D.G., 

Mclntyre, A., Mix, A.C., Molfino, 

B., Morley, J.J., Peterson, L.C., 

Pisias, N.G., Prell, W.L., Raymo, 

M.E., Shackleton, N.J., and 

Toggweiler, J.R., 1992, On the 

structure and origin of major 

glaciation cycles: 1. Linear 

Responses to Milankovitch Forcing: 

Paleoceanography, v. 7, p. 701-738.

Imbrie, J., Berger, A., Boyle, E., 

Clemens, S., Duffy, A., Howard, W., 

Kukla, G., Kutzbach, J., Martinson, 

D., Mclntyre, A., Mir, A., Molfino, 

B., Morley, J., Peterson, L., Pisias, 

N., Prell, W., Raymo, M., 

Shackleton, N., and Toggweiller, J., 

1993, On the structure and origin of 

major glaciation cycles: 2. The

49
100,000-year cycle: 

Paleoceanography, v. 8, p 699-735.

Imbrie, J., and Imbrie, J.Z., 1980, 

Modeling the climate response to 

orbital variations: Science, v. 207, p. 

943-952.

Muller, R.A., 1994, Glacial cycles and 

extraterrestrial accretion: Lawrence 

Berkeley Laboratory Report, LBL35665, Berkeley.

Muller, R.A. and MacDonald, G.J., 

1995, Glacial cycles and orbital 

inclination: Nature, v. 377, p. 107- 

108.

Muller, R.A. and MacDonald, 1997, 

Glacial Cycles and Astronomical 

Forcing: Science, v. 277, p 215-218.

Quinn, T.R., Tremaine, S., and Duncan, 

M., 1991, A three million year 

integration of the Earth's orbit: 

Astronomical Journal, v. 101, p 

2287-2305.

Winograd, I.J., Coplen, T.B., Landwehr, 

J.M., Riggs, A.C., Ludwig, K.R., 

Szabo, B.J., Kolesar, P.T., and 

Revesz, K.M., 1992, Continuous 

500,000-year climate record from 

vein calcite in Devil's Hole Nevada: 

Science, v. 258, p 255-260.

50
Tropical Atlantic Paleoceanography Over the Past 

580 Kyrs: High-Resolution Records from the

Cariaco Basin

Larry C. Peterson, Rosenstiel School of Marine and Atmospheric Science, University of

Miami, Miami, FL 33149

Gerald H. Haug, University of Southern California, Los Angeles, CA 90089

Thomas F. Pedersen, Department of Earth and Ocean Sciences, University of British 

Columbia, Vancouver, B.C., Canada V6TIZ4

Daniel M. Sigman, Department of Geosciences, Princeton University, Princeton, NJ

08544

Introduction

Ocean Drilling Program (ODP) Site 1002 is located in the Cariaco Basin, a 

structural depression on the northern continental shelf of Venezuela, which, after the Black 

Sea, is the largest anoxic marine basin in the world. The Cariaco Basin is well positioned to 

record a detailed history of Trade Wind-induced upwelling along the southern margin of the 

Caribbean, as well as surface ocean changes that result from variations in the large-scale 

circulation of the Atlantic. Previous studies have shown that Cariaco Basin sediments 

record environmental variability recorded to large-scale climatic and oceanographic 

processes (Overpeck and others, 1989; Peterson and others, 1991; Hughen and others, 

1996, 1998; Lin and others, 1997; Haug and others, 1998). Sediments collected at ODP 

Site 1002 (10°42.4'N, 65°10.2'W; water depth: 893 m) extend the Cariaco Basin 

paleoceanographic record back to ~ 580 kyrs BP and provide an unparalleled opportunity 

for high-resolution studies of tropical Atlantic climate in the late Quaternary, including 

Marine Isotope Stage (MIS) 11.

Along its northern margin, the Cariaco Basin is separated from the open Caribbean 

by the shallow Tortuga Bank that extends from Margarita Island to Cabo Codera on the 

Venezuelan mainland. The deepest connections are at 147 m water depth near Farallon 

Centinela at the western end of the basin and near 120 m between Tortuga and Margarita 

Island (Richards, 1975; Peterson and others, 1991). These shallow sills restrict horizontal 

exchange with the open Caribbean and cause anoxic conditions today below about 300 m in 

the basin, as high oxygen demand created by surface water production exceeds the limited 

rate of deep water ventilation. The surface water production in the Cariaco is supported by 

upwelled, nutrient-rich, sub-thermocline waters that enter from the open Caribbean (e.g., 

Richards, 1975; Peterson and others, 1991). Upwelling along the Venezuelan coast that 

feeds biological production in Cariaco surface waters is driven by the Trade Winds and 

shows a large seasonal signal forced by the annual migration of the Intertropical

51
Convergence Zone (ITCZ) in the Atlantic Ocean. The strongest Trade Winds and Ekmaninduced upwelling occur during the winter dry season when the ITCZ is at its southernmost 

position. In the summer, when the ITCZ moves north, the Trade Winds diminish, 

upwelling decreases or shuts off, and the regional rainy season is triggered north of about 

5°N. This alternation of a dry upwelling season and a rainy non-upwelling season produces 

laminated sediment sequences consisting of seasonally alternating light-colored planktonrich layers and darker-colored terrigenous grain-rich layers (Peterson and others, 1991; 

Hughen and others, 1996).

Site 1002 Stratigraphy and Potential for High-Resolution Studies

The major drilling objectives at Site 1002 were to recover a continuous and 

undisturbed late Quaternary stratigraphic section that could be used to 1) document how 

climate change in the southern Caribbean and northern South America relates to climatic 

forcing mechanisms and to global-scale change, especially to high latitude changes 

recorded in ice cores and in other high-deposition rate marine sediment sequences; 2) study 

the rates and magnitudes of tropical climate change at interannual to millennial time scales 

over the last several glacial-interglacial cycles; 3) examine the stability of tropical climate in 

response to past changes in large-scale global boundary conditions; and 4) to study the 

relationships between climate variability and processes that influence the burial of organic 

carbon in anoxic settings. The recovery objectives were successfully achieved with the 

drilling of five holes at Site 1002, two of which were single mudline cores taken for 

geochemical studies, and three that were taken for high-resolution paleoclimatic 

reconstructions and that together penetrated to a maximum depth of 170.1 meters below 

surface.

The late Quaternary sediments at Site 1002 are generally dominated by terrigenous 

sediment components with variable biogenic contributions of nannofossils, diatoms, 

foraminifers (both planktic and benthic), and pteropods. Throughout much of the 

sequence, the presence of aragonitic pteropods is characteristic of the generally excellent 

preservation of calcareous microfossils. Much of the sediment at Site 1002 is laminated, 

indicating deposition under largely anoxic conditions. Nevertheless, significant subsurface 

intervals showing clear evidence of bioturbation testify to a history of oscillation between

oxic and anoxic environments in the deep basin. The present 818O-based age model 

indicates a basal age of -580 kyrs BP for the recovered Cariaco Basin sequence, yielding 

an average sedimentation rate of about 35 cm/kyrs (350 m/m.y.). This rate is in line with 

sedimentation estimates previously derived for the uppermost sediment column and ensures 

the Cariaco Basin's role as an important archive of high-resolution paleoenvironmental 

information.

52
Nutrient Cycling and Production Changes in the Cariaco Basin

Throughout the Holocene sea level highstand, Trade Wind-induced changes in 

upwelling have affected surface production in the Cariaco Basin. Over longer time-scales, 

however, it is clear that sea level must also play a role in modulating surface productivity in 

the basin as the shoaling of sill depths during glacial lowstands appears to restrict the input 

of nutrient-rich subsurface waters from the open Caribbean. Although numerous lines of 

evidence are being pursued to reconstruct and unravel paleoproductivity in the Cariaco 

Basin and its relationship to climatic, oceanographic, and sea level variability, results of 

recent nitrogen isotope studies (Haug and others, 1998). are highlighted here. The results 

from ODP Site 1002 indicate that there have been large glacial/interglacial variations in N2 

fixation in the Cariaco Basin, with higher rates during interglacial periods. This sense of 

change is not easily explained by a trace metal dependence of N-fixers (Falkowski, 1997), 

since trace metal supply was unlikely to have been lower during glacial times. Based on our 

work and on previous studies, we suggest that nitrogen fixation responds to 

glacial/interglacial changes in the [NO3]/[PO4] ratio of the nutrient supply to Cariaco surface 

waters, driven by changes in the rate of denitrification. The N2 fixation response may stem 

from changes in denitrification within the Cariaco Basin itself, or it may be driven by 

previously recognized glacial/interglacial variations in open ocean denitrification (Altabet 

and others). If such an N2 fixation response occurs more broadly in the global ocean, then 

it would tend to compensate for large denitrification-driven changes in the ocean nitrate 

reservoir on glacial/interglacial timescales, and work against the occurrence of large 

changes in the [NO3 ]/[PO4] ratio during the Quaternary.

Although the evidence reported here suggests a response of N2 fixation to changes 

in denitrification, it remains to be seen exactly how tightly these two processes are coupled. 

If the coupling is tight, nitrate reservoir changes could only be driven by changes in the 

oceanic phosphate reservoir. Given the long residence time of dissolved phosphate (-16-38 

kyr) (Ruttenberg, 1993), large changes in the oceanic P reservoir at rather abrupt 

glacial/interglacial transitions are unlikely. Consequently, depending on the tightness of the 

coupling between denitrification and N2 fixation, our findings may argue against the 

nutrient reservoir explanation for glacial/interglacial atmospheric CO2 changes.

References:

Altabet, M.A., Francois, R., Murray,

D.W., and Prell, W.L. 1995, Haug, G.H., Pedersen, T.F., Sigman, 

Climate-related variations in D.M., Calvert, S.E., Nielsen, B., 

denitrification in the Arabian Sea from and Peterson, L.C. 1998, 

sediment 15N/14N ratios: Nature, v. Glacial/interglacial variations in 

373, p. 506-509. production and nitrogen fixation in

the Cariaco Basin during the past 580

Falkowski, P.G., 1997, Evolution of the kyr: Paleoceanography, v. 13, p. 

nitrogen cycle and its influence on the 427-432. 

biological sequestration of CO2 in the 

ocean: Nature, v. 387, p. 272-275.

53
Hughen, K.A., Overpeck, J.T., Lehman, 

S.J., Kashgarian, M., Southon, J., 

Peterson, L.C., Alley, R., and D.M. 

Sigman, 1998, Deglacial changes in 

ocean circulation from an extended 

radiocarbon calibration: Nature, v. 

391, p. 65-68.

Hughen, K.A., Overpeck, J.T., 

Peterson, L.C., and Trumbore, S.E. 

1996, Rapid climate changes in the 

tropical Atlantic region during the last 

deglaciation: Nature, v. 380, p. SI54.

Lin, H.-L., Peterson, L.C., Overpeck, 

J.T., Trumbore, S.E., and Murray, 

D.W. 1997, Late Quaternary climate

change from 818O records from 

multiple species of planktonic 

foraminifera: High-resolution records 

from the anoxic Cariaco Basin, 

Venezuela: Paleoceanography, v. 12, 

p. 415-427.

Overpeck, J.T., Peterson, L.C., Kipp, 

N.G., Imbrie, J., and Rind, D. 1989, 

Climate change in the circum-North 

Atlantic region during the last 

deglaciation: Nature, v. 338, p.553- 

557.

Peterson, L.C., Overpeck, J.T., Kipp, 

N.G., and Imbrie, J. 1991, A highresolution Late Quaternary upwelling 

record from the anoxic Cariaco Basin, 

Venezuela: Paleoceanography, v. 6, 

p. 99-119.

Richards, F.A., 1975, The Cariaco Basin 

(Trench): Oceanography and Marine 

Biology: Annual Review, v. 13, p. 

11-67.

Ruttenberg, K.C., 1993, Reassessment 

of the oceanic residence time of 

phosphorus: Chemical Geology, v. 

107, p. 405-409.

54
Millenial-Scale Climate Variability in the Western 

North Atlantic During Marine Isotope Stages 11 and 12:

Results from ODP Leg 172

M. S. Poll, R. C. Thunell, University of South Carolina, and D. Rio, University of Padova

The time period represented by oxygen isotope stages 11 and 12 (approximately 480 to 362 

ka) contains the most extreme climatic variations of the late Pleistocene. The MIS 12-11 transition 

is the largest of the last 650 kyrs, is preceded by one of the most severe glacial stages of the late 

Pleistocene, and is followed by a long and warm interglacial. These changes in the climate system 

are not associated with significant changes in the Earth's orbital configuration: insolation changes 

are relatively small at this transition, and MIS 11 is a time of low orbital eccentricity and low 

precessional amplitude. Recent work suggests that sea level during glacial stage 12 was -140 m 

below present (Rohling and others, 1998). During interglacial stage 11, temperatures were warmer 

and sea level was -20 m higher than during the Holocene.

Ocean Drilling Program Leg 172 was designed to recover a sequence of high deposition rate 

sediment cores from sediment drifts that can be used to document changes in the properties and 

circulation patterns of intermediate and deep-waters in the North Atlantic during the late Pliocene 

and Pleistocene. In order to address this problem, a bathymetric transect of eleven sites has been 

cored between 1,300 to 4,600 m water depth on the Carolina Slope (CS), Blake-Bahama Outer 

Ridge (BBOR) and Bermuda Rise (BR). Sites were chosen so that at least one lies within each 

modem watermass, and one lies at each boundary between watermasses.

The recognition of stages 11-12 was based on the extinction of the calcareous nannofossil 

Pseudoemiliania lacunosa: a biostratigraphic event that occurs within stage 12. We sampled two 

sites (1058 and 1063, located on the Blake Bahama Outer Ridge and the Bermuda Rise, 

respectively) at an average time interval of -500 yrs, and all the other sites at an average time 

interval of -3000 yrs. Sedimentation rates at these sites tend to be high (usually greater than 

lOcm/kyr) allowing us to examine high frequency climate and oceanographic changes during the 

stage 11-12 time period using color reflectance, calcium carbonate content and benthic 

foraminiferal carbon and oxygen isotopes. Using both %CaCO3 and lightness data, we calculated 

average sedimentation rates between MIS 9 and 13. The results indicate increasing values from the 

shallower to the deeper sites, except for sites 1062 and 1063.

Preliminary results show an excellent correspondence between color reflectance data 

(lightness L) collected onboard and carbonate content, thus confirming that lightness is a good 

proxy for carbonate content in this region. The typical western North Atlantic glacial-interglacial 

changes in %CaCO3 (with higher values during interglacials) are evident for this time interval. The 

stage 11-12 transition is characterized by abrupt changes in the carbonate content at the deepest 

sites (bathed today by Antarctic Bottom Water, AABW) and by somewhat smoother changes at the 

shallower sites (North Atlantic Deep Water, NADW). Our high resolution data indicate that MIS 11 

is marked by three distinct carbonate peaks (x, y and z). At sites 1063 and 1062, the records

55
clearly show 4 to 5 carbonate peaks during early MIS 12, followed by an interval of uniformly low 

carbonate values, suggesting some instability preceding the glacial maximum. The carbonate peaks 

are similar to features previously reported for this region for the last glacial (Keigwin and Jones, 

1994) and correlated to the interstadial events contained in ice cores. Thus, our data suggest the 

occurrence of similar interstadial events during stage 12.

The 818O record for Site 1063 contains a 2.2%o change at the MIS 12-11 transition. Since 

the estimated ice-volume contribution to this signal is ~1.5%o (Chappell, 1998), the residual change 

is indicative of a bottom water temperature change of 3-4°C. This is significantly larger than most 

previous estimates of glacial-interglacial changes in bottom water temperatures.

The 813C data show a close covariance with percent CaCO3 , particularly at site 1063, 

suggesting that the two proxies are responding to the same forcing. Previously published data from 

the BBOR and BR areas for the last 140 kyrs show similar sub-orbital scale changes in carbonate 

patterns, and have been attributed to changes in terrigenous dilution and bottom water chemistry 

(Keigwin and Jones, 1994). Our data indicate that the bottom water mass bathing the Bermuda

Rise during MIS 12 was more enriched in the AABW component than during MIS11, when 813C 

values are close to present day NADW values. Additionally, the periods of low carbonate content 

during interglacial MIS 11 are interpretted to be times of reduced NADW formation.

References:

Chappell, 1998, Jive talking: Nature, v. 394, 

p. 130-131.

Keigwin, L. and Jones, G. 1994, Western 

North Atlantic evidence for millennialscale changes in ocean circulation and 

climate: Journal of Geophysical 

Research, Oceans, v. 99, no. 6, p.

12397-12410.

Rohling, E. J. , Fenton, M. , Jorissen, F. J., 

Bertrand, P., Ganssen, G., and Caulet, 

J. P., 1998, Magnitudes of sea-level 

lowstands of the past 500,000 years: 

Nature, v. 394, p. 162-165.

56
The Vostok Ice Core in the Context of Stage 11

D. Raynaud, Laboratoire de Glaciologie et Geophysique de 1'Environnement /CNRS, B.P. 96,

38402 Saint Martin d'HEres cedex, France

Ice core records compliment the marine and continental records. They are unique in 

providing the most direct atmospheric signature of the past climatic and environmental 

changes. The information is obtained by measuring the composition of the ice itself and of 

the gas entrapped. The ice record gives access to paleoclimate series including polar 

temperature and precipitation rate, atmospheric trace gases, wind strength, aerosol fluxes of 

marine, volcanic, terrestrial, cosmogenic and anthropogenic origins.

The recently extended Vostok ice core record provides a unique, complete, and 

undisturbed picture of the atmospheric changes over the last 4 climatic cycles (Petit and 

others, 1997 ; Petit and others, in press). Most of the variability occurs with periodicities 

corresponding to that of the precession, tilt and eccentricity of Earth's orbit with the 

dominance of the 100 ka cycle. The record confirms that greenhouse gases and ice volume 

changes have played the role of strong amplifiers of the external insolation forcing to 

stimulate the observed glacial-interglacial climatic changes.

In the context of the interglacial periods of the late Quaternary, including stage 11, the 

Vostok record shows interglacials which differ in shape. Antarctic temperature was warmer 

and atmospheric CO2 and CH4 higher during interglacial 5.5 and 9.3 than during the 

Holocene and interglacial 7.5. The record, which can be interpreted with confidence down to 

3310 m, also documents at least the last part of stage 11 (11.3). It does not show stage 11- ice 

especially warm or with CO2 and CH4 concentrations particularly high (the properties of this 

stage 11 - ice are similar to those during the Holocene or stage 7.5). Below 3310 m there are 

indications that the record is disturbed, probably because of ice flow anomalies affecting the 

deepest layers of the ice sheet (Petit and others, in press). So, we cannot be sure that the 

undisturbed Vostok ice sequence provides a record of the extreme condition (the wannest and 

the highest in terms of greenhouse gas concentrations) of stage 11.

This "frustrating" situation is not without solution. There are, indeed, potential sites 

in Antarctica (but not in Greenland) which may deliver an undisturbed record going back to 

stage 12 (i.e. with a complete stage 11). Candidates are, for instance, sites in the vicinity of 

Vostok but with thicker ice, or sites on a dome (like Dome A in East Antarctica) with a cold 

base (in contrast with the Vostok ice under which exists a deep subglacial lake).

References:

Petit, J. R. , Basile, I. , Leruyuet, A., Petit, J.R. and others, in press, Climate 

Raynaud, D. , Lorius, C. , Jouzel, J. and atmospheric history of the past 

and Stievenard, 1997, Four climate 420,000 years from the Vostok ice 

cycles in Vostok ice core: Nature, v. core, Antarctica. 

387, p. 359-360.

57
The continental record of Stage 11

Denis-Didier Rousseau, Paleoenvironnements et Palynologie, Institut des Sciences de

1'Evolution (UMR CNRS 5554), Universite Montpellier H, case 61, place E. Bataillon,

34095 Montpellier cedex 05, France and Lamont-Doherty Earth Observatory of Columbia

University, Palisades, New York 10964

Terrestrial Quaternary stratigraphy in Europe has been strongly influenced by the 

Alpine glaciation chronology on the one hand and the recognition of temperate interglacial 

intervals on the other hand. Because both kinds of records did not occur in the same 

location, different interpretations and correlations occur in the stratigraphical community 

(Sarnthein, and others, 1986). Thus, there is uncertainty about which terrestrial 

interglacial correlate with marine isotope stage 11. Here, I adopt the view of Kukla (in 

Smiley and others, 1991) who determined, by comparing marine and continental records, 

that marine stage 11 corresponds to the terrestrial interglacial named Holsteinian in 

northern Europe (Fig. 1).

Identifying the continental stage 11 requires study of long sequences which 

yield superimposed climatic cycles and have reliable chronostratigraphies (Fig. 2). 

However, time resolution is not always good enough to describe in detail the observed 

climatic and environmental changes. The following review will be three fold: pollen and 

lake sequences, loess series, and an example of a particular European fauna! record.

-60

iscus bi 

du Bouche

*s::*:*":*:*:::*:*:: 

x'*'x':Tuie Lak

Tenaghi Philippon

&"

Hula

Changwu

-60

-180 -120 120 180

Fig. 1. Location of the different records discussed in the text. Plain 

circles corresponds to individual long sequences; plain squares 

correspond to the occurrence of the European mollusk localities of 

marine stage 11.

59
OCEAN LOESS

TER

CLASSICAL SYSTEMS

N. AMERICA

AGE O 18 SPECMAP GLC CK CHINA C. USE GL INT ALPS 

86

I

n

ir

n

B

D

L1

si SON

L.ILL

-L H.ILL

N

LJ

R

GLAC INT

UEICHSEL

URRTHE

EEMEEM

EDO

Si* SRRLE

rF

LS E-ILL LHTE ELSTER

MIS 11

Fig. 2. Continental records of MIS 11. Marine isotope stage 11 

according to SPECMAP and comparison with the loess (European, general 

and Chinese), North American, European Alpine and North European 

Plain Quaternary Stratigraphies, (from Kukla,1991. modified)
Pollen and lake records

Pollen and lake sequences yield numerous records of stage 11 which permit the 

characterization of environmental changes with varying magnitude because of the 

geographical location and the time resolution reconstructed. Cores taken at Tule Lake in 

North America record MIS 11 (Adam and others, 1989). However, the time resolution is 

so poor that no interesting information can be deduced for this time interval.

Europe, although located on the eastern bank of the Atlantic Ocean, and thus 

directly under the influence of the variations of the thermo-haline circulation, shows at 

least 4 well developed long lacustrine pollen series, among which 3 recorded marine 

isotope stage 11 : Lac du Bouchet-Praclaux in the French Massif Central, lonnina, and 

Tenaghi Philippon in Greece (Fig. 2). The variations in the aboreal pollen curve allow the 

recognition of several climatic cycles, where interglacials are characterized by a logical 

succession of vegetation leading to high percentages of arboreal pollen grains.

In Lac du Bouchet-Praclaux, the Holsteinian is well recorded and characterized 

by few Carpinus, while Abies andFagus are dominant (Reille and de Beaulieu, 1995). 

A small interval is marked by the occurrence of Taxus, and some thermophilous taxa like 

Bwcus and Vitis are present. The interpretation of this vegetation is that the interval was 

not warmer than the other following interglacials but moister (Fig. 3).

At lonnina (Tzedakis, 1994) (Fig. 4), Stage 11 is well developed. The pollen 

concentration is the highest during the early part of Stage 11 and interpreted as the 

occurrence of a dense forest environment. It is characterized by high pollen concentration 

of warm taxa such as Bwcus, Ulmus, Zelkova, Alnus or even Fagus, the latter indicating 

low precipitation and high temperate conditions. This record is in complete agreement 

with that in Tenaghi Philippon in Macedonia (Wijmstra and Young, 1992) which recorded 

the past 700 ka and showed a strong terrestrial biomass development during MIS 11 .

Two long sequences in Israel show a different pattern (Fuji and Horowitz, 1989; 

Horowitz, 1989). There, interglacials are interpluvial with a strong influence of the 

Sahara and reduced precipitation. The comparison between northern and southern Israel 

indicates different conditions, implying that a steep gradient occurred between N and S 

(Fig. 5). The vegetation in northern Israel indicates a desert environment during MIS 11 

while southern Israel experienced moist, steppe conditions. The two areas are, at present 

time, under contrary conditions (Fig. 5).

In Japan, the Biwa sequence (Fuji and Horowitz, 1989) covers the last 1.5 

Myrs. The sequence shows that the vegetation succession during the different interglacials 

was similar to present conditions, especially under the influence of marine currents (Fig. 

6). However, MIS 11 indicated warmer environment than during present time.

Finally, the Funza Bogota pollen record in Colombia shows a complete sequence 

of the past 3.5 Myrs (Hooghiemstra and Melice, 1994; Hooghiemstra and others, 1993).

61
Zones

Pollen 

Fig.3. Lac du Bouchet pollen sequence, a) Comparison of

the Ap, Ap-Pinus percentages with the Specmap S-^O 

curve. Indication of the stratigraphy, b) Pollen diagram (selected trees) of the Holsteinian from Reille & 

De Beaulieu 1995 modified

VO

(N
Depth 

(m)

0

20

40

60

80

100

120

140

160

Ap/NAP Ap concentration 

(x 1000 grains/cm3)

Marine Isotope 

Stages

0 20 40 60 80 100 0 200 400 600

Fig. 4. Pollen sequence at lonnina (Greece). 

Variation in AP-NAP% on the left, in AP 

concentration, correlation with the marine isotope 

chronology, from Tzedakis 1994 modified.

63
(FROM : IMBKIE et al. .198-1)

s.McxrniKn STACK

ISTAXUARU DEVIATION I'XITSI

I R

SOUTH-DEAD SEA NOKTH-HULA

J.'KIIMM+WMMI 

.t-7(XX)«+:jTi<K)

3,'.XH)IW+ 2WXMI

JAPAN

LAKE BIWA 

£ V

2 HUM"

t -I- 

-I 

t l 

I -2 

C -2

t-7 

C-9

MIS 11

Fig. 5. Comparison between the long terrestrial pollen records in Israel and Japan, and correlation 

with SPECMAP chronology, (from Fuji and Horowitz 

1989 modified).

64
§ 2000

* High plain of Bogoli ~ Xerophytic vegetation ^Magdalene river « Foreit line

500 600 700 800 900 1000 1100 1200 1300 MOO 1500 

<YR) 

400 500 600 700 BOO 900 1000 1100 1200 1300 1400 '500

VO

0 100 200 300 400 500 600 700 800 900 1000 MOO 1200 1.300 1400 1500

Fig. 6 . Pollen sequence of Funza Bogota (Colombia) a) location and variation of the vegetation according to the present interglacial and last glacial maximum scenarios, b) variations 

of Ap and Alnus percentages versus time. Indication of stage 11 interval.from Hooghiemstra and others. 1993 modified
The AP curve indicates that during isotope stage 11, the upper limit of the Andean forest 

was higher than 3000 m with a temperature higher than 14.8°, which is the present value. 

However, a high percentage ofAlnus is recorded. In the Bogota area, Alnus lives mostly 

in swampy zones and its high concentration could be interpreted as an indication of high 

humidity (Fig. 5).

A long pollen sequence in Australia also recorded marine isotope stage 11 

(Williams and others, 1993). However, no interpretations in terms of temperature or 

moisture are possible because no pollen is preserved during that interval (Singh and 

Geissler, 1985). There are, nevertheless, charcoals which indicate that this interval was a 

period with less fires than the following interglacials (Fig. 6).

Lake Baikal, in another context, provides a record of continental climate for the 

past 5 Ma (Williams and others, 1997). The study of the biogenic silica flux shows that of 

the past 800 ka, the production during MIS 11 was among the highest - indicating high 

blooming of diatoms in Spring.

Loess record

Although both are continental records, loess sequences and pollen records 

correspond to different environments. Loess sediment occurrs mostly in the northern 

hemisphere at the southern margin of former ice-sheets or on the pathway of winds 

connecting high pressure to low pressure cells. Loess sequences can provide reliable 

records of past climatic changes especially for long sequence spanning several cycles. In 

China, the sequences within the Central Chinese loess plateau yield a record of the past 

2.4 Myrs, an includes a complete Quaternary record (Kukla, 1987). The succession of 

loess and soil units and magnetic scale permit correlations with marine records. The 

analysis of the magnetic susceptibility has been correlated with the eolian dust record from 

Pacific cores (Hovan, and others, 1991) and thus is a good climatic index, even if the 

interpretation for paleosols also include bacterial activity. In the Chinese series, marine 

isotope stage 11 is represented by a soil complex named S4 within the Upper Lishi 

formation. The magnetic susceptibility shows high values that are not the highest in the 

record. However, the study of the Iron Oxide ratio (an index of weathering) does show 

the highest values during the deposition of soil S4 (Guo and others, 1998). The 

interpretation is that, compared to the present time, the climatic conditions were the wetter 

during marine stage 11. This conclusion is supported by the interpretation of the pollen 

content in Luochuan. A rich pollen assemblage with Anacardiaceae and Thalicrum lead 

Wang and others (in Kukla, 1987) to conclude that the soil surface during S4 was wetter 

compared to the soils of the Lower Lishi formation. A reinforcement of the summer 

monsoon regime during marine isotope stage 11 over central China must then be 

considered (Fig. 8).

66
MARINE 

XYGEN ISOTOPE 

RECORD

AUSTRALIA

LAKE GEORGE

CHARCOAL PARTICLES 

(abundance values)

Fig.7.Comparison between marine isotope record and the charcoal and pollen sequences from Lake George (Australia). (from 

Williams and others 1993 modified).

67
100 -

200 -300 -

400 -

500 -

600 -

700 L

VO

oo

Fig. 8 Variation of the weathering intensity in the Chinese loess plateau.a) location of the Changwu sequence, b) variation in the Fed/Fet ratio representing the weathering

intensity.(from Quo and others 1998 modified).
69

<0 

.Q 

LLJ

Q.

55

PLEISTOCENE 

Middle | Up. 

-g S-jiSaalian

CO <DCM 

QL

w

4J 

HJ -H 0 W 

-H O 

W J2 S & 

-H V -q T3 

X! >i -U Q) u ^3«

Om 4J Q) ° &«^S C ^ O Q) o a c w

-H a 

t! ^ § o w 

2 -H -H W 

-Q s ^ 4J Q) -H nj -H o H -H rn W rH 

 *-> M d O W OJ U & in 

'-3 o .2 o S 

2 -5 1 2 3 5 U &^, f S I . J 3 5 

4J g ^ 4J 7 

^S ^ g 2 

^l S » 8 H' ^ Dl ® 'pi, 

9J * -H JJ 4J gC - 5> W ° - N Co

-O 3 M "S ^ o5 S $ o ^ Q,X! M X! <" u "* m w J 

X! Jj "u U i-j 

"3|& S£ 

^2 (0 ^ w C »-> 

n * 3 H - w 

"~l ^ rH 4-1 

8«3« I 0 

1 g 3 > ^ S 3 

5 -^ 5 ° 8 o *i ^ -H c S. H § § OM S W > O -H r; H W Q, 4J S « -2 3 -H « 3,H tJ-nfl 3 

3S2B&S 

"ft 5 7! -H e % *c "° o c 

""I ^-» ri " -3 * ~ c y s S"^* ^ 1 g

}H C s Q) M 

nj « «U n "O 3 

rH q ft C W d nj nj (o 

- u >H 

a\

u u VH ~ -H -H bi oj » oj M o x! a 

 t "\ J ~I Dl O ui 

4J H W tn i w»i o tn q ;H -H 

U r^J 

(0 , a nj 
A particular European fauna! event

In Western Europe, loess sequences also recorded the equivalent of stage isotope 

11. In the series of St. Pierre-les-Elbeuf in the Seine Valley, north-west France, the loess 

sequence is mainly composed by the alternation of loess and soil units (Lautridou and 

Verron, 1970). Elbeuf IV, the soil complex equivalent to MIS 11 shows the peculiarity of 

including a tufa (Fig. 9). This sediment yielded a terrestrial malacofauna which shows an 

unusual composition by comparison to the present fauna (Rousseau, 1992; Rousseau and 

others, 1992). A few kilometers to the east, still in the Seine Valley, another tufa deposit 

which base has been dated by U/Th to about 400 ka yielded a similar fossil terrestrial 

malacofauna. Other sites in northern France, southeastern England (Hoxnian age) and 

south-western Germany yielded that malacofauna and have been correlated together. The 

composition of the snail assemblage is very special. The forest species are dominant 

indicating a temperate conditions, but moisture was high too. Moreover, whereas the 

identified species one still living today in the surroundings of the localities, other show at 

the present time a rather different pattern. Some are living in Central Europe, some are 

southern (one is endemic of Bayonne area), one is endemic of northern area of British 

Islands (Fig. 9). Two species are fossil among which one is related to a subgenus which 

present distribution is endemic of the Canary Islands (Rousseau and Puissegur, 1990). 

Also plant macrofossils include Mediterranean and tropical trees, and among them the 

Laurel of the Canary Islands. Using the Biome concept, this particular assemblage was 

named the Lyrodiscus biome. According to this study, MIS 11 climate in western Europe, 

or at least the second half, with regards to the stratigraphic position of the tufa above the 

paleosol Elbeuf IV in St Pierre-les-Elbeuf, was warmer but also moister than today.

Conclusions

Terrestrial records of stage 11 show contrasted conditions with a marked N/S 

gradient in Europe indicating higher temperature than today in some places but generally 

more humid conditions in mid-latitudes while low precipitation in the Mediterranean 

basin. On the contrary, the SE Asian monsoon was reinforced, fires reduced in SE 

Australia and the high plain of Bogota experienced hot and wet conditions.

Acknowledgments

Thanks to Dick Poore for the invitation to present this review and to the different 

participants of the Stage 11 workshop in San Francisco for fruitful discussions, to Dr ZT 

Guo for providing the Changwu values of the weathering index and to Dr. JL de Beaulieu 

for the Lac du Bouchet-Praclaux synthetic diagram. This is ISEM contribution 99-043.

References

Adam, D.P., Sama-Wojcicki, A.M., Palaeoclimatology, Palaeoecology, 

Rieck, H.J., Bradbury, J.P., Dean, v. 72, p. 89-103. 

W.E., and Forester, R.M., 1989,

Tulelake, California : the last 3 Fuji, N., and Horowitz, A., 1989, 

million years.: Palaeogeography, Brunhes epoch paleoclimates of

70
Japan and Israel: Palaeogeography, 

Palaeoclimatology, Palaeoecology, 

v. 72, p. 79-88.

Guo, Z.T., Liu, T.S., Fedoroff, N., 

Wei, L.Y., Ding, Z.L., Wu, N.Q., 

Lu, H.Y., Jiang, W.Y., and An, 

Z.S., 1998, Climate extremes in 

loess of China coupled with the 

strength of deep-water formation in 

the North Atlantic: Global and 

Planetary Change, v. 18, p. 113- 

128.

Hooghiemstra, H., and Melice, J.L., 

1994, Pleistocene evolution of 

orbital periodicities in the highresolution pollen record Funza I, 

Eastern Cordillera, Colombia: 

Special Publications International 

Association Sedimentologists, v. 19, 

p. 117-126.

Hooghiemstra, H., Melice, J.L., 

Berger, A., and Shackleton, N.J., 

1993, Frequency spectra and 

paleoclimatic variability of the highresolution 30-1450 ka Funza I pollen 

record (Eastern Cordillera, 

Colombia): Quaternary Science 

Reviews, v. 12, p. 141-156.

Horowitz, A., 1989, Continuous pollen 

diagrams for the last 3.5 M.Y. from 

Israel : vegetation, climate and 

correlation with the oxygen isotope 

record, in G. Kukla (ed.) "Long 

continental Records of Climate".: 

Palaeogeography ,Palaeoclimatology, 

Palaeoecology, v. 72, p. 63-78.

Hovan, S.A., Rea, D.K., and Pisias, 

N.G., 1991, Late Pleistocene 

continental climate and oceanic 

variability recorded in northwest 

Pacific sediments.: 

Paleoceanography, v. 6, p. 349-370.

Kukla, G., 1987, Loess Stratigraphy in 

Central China.: Quaternary Science 

Reviews, v. 6, p. 191-219.

Lautridou, J.P., and Verron, G., 1970, 

Paleosols et loess de Saint-PierreLes-Elbeuf (Seine-Maritime): 

Bulletin de 1'Association fransaise 

pour 1'Etude du Quaternaire, v. 23- 

24, p. 145-165.

Reille, M., and de Beaulieu, J.L., 1995, 

Long Pleistocene Pollen Records 

from the Praclaux Crater, SouthCentral France: Quaternary 

Research, v. 44, p. 205-215.

Rousseau, D.D., 1992, Is causal 

ecological biogeography a 

progressive research program?: 

Quaternary Science Reviews, v. 11, 

p. 593-601.

Rousseau, D.D., and Puissegur, J.J., 

1990, Phylogenese et biogeographie 

de Retinella Lyrodiscus) Pilsbry 

(Gasteropoda; Zonitidae).: Geobios, 

v. 23, p. 57-70.

Rousseau, D.D., Puissegur, J.J., and 

Lecolle, F., 1992, West-European 

molluscs assemblages of stage 11: 

Climatic implications.: 

Palaeogeography,

Palaeoclimatology, Palaeoecology, 

v. 92, p. 15-29.

Sarnthein, M., Stremme, H.E., and 

Mangini, A., 1986, The Hosltein 

interglaciation: time-stratigraphic 

position and correlation to stableisotope stratigraphy . of deep-sea 

sediments: Quaternary Research, v. 

26, p. 283-298.

Singh, G., and Geissler, E.A., 1985, 

Late Cainozoic history of fire, 

vegetation, lake levels and climate at 

Lake george, New South Wales, 

Australia. Philosophical Transactions 

Royal Society of London, Series B, 

v. 311, p. 379-447.

Smiley, T.L., Bryson, R.A., King, 

I.E., Kukla, G.J., and Smith, G.I., 

1991, Quaternary paleoclimates, in 

Morrison, R.B., ed., Quaternary 

Nonglacial Geology: Conterminous 

U.S. The Geology of North

71
America: Boulder, The Geological 

Society of America, p. 13-44.

Tzedakis, P.C., 1994, Vegetation 

change through glacial-interglacial 

cycles: a long pollen sequence 

perspective: Philosophical 

Transactions Royal Society of 

London, Series B, v. 345, p. 403- 

432.

Wijmstra, T.A., and Young, R., 1992, 

Vegetational and Climatic Transitions 

between Interglacial and Glacial 

Periods during The Last 1 Million 

Years in Northern Greece, in Kukla, 

G.J., and Went, E., eds., Start of a 

Glacial: Series I: Global

Environmental Change: Heidelberg, 

Springer-Verlag, p. 97-112.

Williams, D.F., Peck, J., Karabanov, 

E.B., Prolopenko, A.A., 

Kravchinsky, V., King, J., and 

Kuzmin, M.I., 1997, Lake Baikal 

record of continental climate 

response to orbital insolation during 

the past 5 million years: Science, v. 

278, p. 1114-1117.

Williams, M.A.J., Dunkerley, D.L., De 

Deckker, P., Kershaw, A.P., and 

Stokes, T., 1993, Quaternary 

Environments: Edward Arnold, 

London, 329 p.

72
A Submerged Stage 7 Terrace and Reevaluation of the 

Late Pleistocene Stratigraphy of Oahu, Hawaii

C. E. Sherman, C. H. Fletcher, and K. H. Rubin, Department of Geology and Geophysics, 

School of Ocean and Earth Science and Technology, University of Hawaii, 1680 EastWest Road, Honolulu HI 96822; 808/956-4239; e-mail: csherman@soest.hawaii.edu

Results of sedimentologic and geochronologic investigations of a nearshore 

terrace require a reevaluation of the late Pleistocene stratigraphy and relative sealevel/tectonic history of Oahu. The shallow submerged slope of Oahu consists of a 

shallow-dipping shelf extending from the shoreline out to the 20 m contour where there 

is a sharp break (wall) down to 30 m forming the start of a deeper terrace. The 

composition, as well as shoreward zonation of facies, suggests that the nearshore terrace 

represents an in situ fossil reef complex. Th-U ages of in situ corals indicate that the 

terrace complex is entirely Pleistocene in age and suggest that the bulk of the feature is 

composed of a fossil reef complex formed during marine oxygen isotope stage 7.

The emerged carbonate record on Oahu contains two well-identified upper 

Pleistocene formations. The Kaena Formation, which reaches elevations as high as +30 

m, has been correlated with marine oxygen isotope stage 13 or 15. The Waimanalo 

Formation, which reaches elevations as high as +12.5 m, has been correlated with marine 

oxygen isotope stage 5e. The age and position of these formations has been used to 

determine the long-term uplift rate for Oahu. In coastal sections, the Waimanalo 

Formation either rests unconformably on the Kaena Formation or is separated from it by 

the Bellows Field Eolianite of undetermined age.

The data presented here suggest relative sea levels on Oahu during stage 7 were 

much lower than sea levels during stage 5e or stage 13/15. In addition, hiatuses in the 

emerged record of Oahu may be accounted for in the nearshore submarine terraces.

73
The Stage 11 Problem as seen at ODP Site 982

C. Stanton-Frazee, D. A. Warnke, California State University, Hayward, CA 94542 

K. Venz, D. A. Hodell, University of Florida, Gainesville, FL 32611

ODP Site 982 (57° 30' N, 15° 32' W, 1133 m water depth) on the Rockall Plateau 

in the North Atlantic, contains a superb history of ice rafting of the last 2 million years, 

tied directly to the stable-isotope record. Here, we concentrate on the time span around 

400,000 ka, namely the State 11 (Holsteinian) interglacial. This interglacial is 

characterized in Alaska by a high sea stand, known as the Wainwrightian Transgression 

(Karmuk Member of the Gubitz Formation) on the North Slope (J. Brigham-Grette, 

personal communication). Because this high sea stand is about 20 m above present sea 

level, planetary ice-volume may have been below present volume, resulting in higher sea 

level (ignoring possible vertical uplift of the North Slope for the purpose of this initial 

discussion).

The combined record from Site 982 shows the following: the strong Stage 12 

glacial was followed by an abrupt transition to Stage 11. This transition, Termination V, 

coincided with the highest ice-rafted debris (IRD) peak of the record. This large, 

Terminal Ice Rafting Event (TIRE) was followed by 23 ka without IRD deposition (only 

1 sample contains some IRD), in turn followed by an interval of only sporadic IRD 

delivery. Because the non-volcanogenic IRD at Site 982 reflects mainly glaciations on 

Greenland, the complete absence of this material during much of Stage 11 may indicate a 

major deglaciation of Greenland. In turn, because of the teleconnection via rising sea 

level to the Westantarctic Ice Sheet (WAIS), a reduction in the size of the WAIS is also 

likely, Therefore, a reduction in planetary ice volume during Stage 11 may partially 

explain the transgression noted in Alaska.

75

77
Appendix 1

Workshop Agenda 

Stage 11 Workshop Crowne Plaza Hotel 5 December, 1998

8:20

8:30

8:50

9:05

9:25

9:40

10:00

10:15

10:35

10:55

11:10

11:35

Introduction and schedule - outline of session

1 - Stage 11 and solar forcing - Richard Muller

discussion 1

2 - The ice-core record - Dominique Raynaud

discussion 2

3 - The sea-level record - magnitude and timing - Julie

discussion 3

break

4 - The continental record of Stage 11 - Denis-Didier

discussion 4

5 - The marine record of Stage 11 - Will Howard

discussion 5

Sutter El

Brigham-Grette

Rousseau

12:00 lunch

1:00 posters and informal discussion Sutter I & II

2:15 - 5:00 formal discussion session - topics to include: Sutter IH

 The continental record - what are the problems- where are the gaps - what types 

and resolution of data are needed

2. The sea-level and ice record - same questions as for the continental 

record

3. Drilling targets - what areas and specific sites offer potential to 

provide new information bearing on data needs and problems.

4. 1999 AGU Symposium

77
Appendix 2

Workshop Participants

John Barren

Julie Brigham-Grette

Lloyd Burckle

Harry Dowsett

Andre Droxler

John Farrell

Chip Fletcher

Christina Gallup

Gerald Haug

Dave Hodell

Will Howard

Daniel Karner

David Korejwo

Ron Litwin

Mitch Lyle

Korie Mielke

Richard Muller

Delia Oppo

Lisa Osterman

Larry Peterson

Serena Poli

Dick Poore

Christina Ravelo

Dominique Raynaud

Yair Rosenthal

Denis Rousseau

Scott Starratt

Dietz Warnke

USGS

UMass

LDEO

USGS

RiceU

JOI

U

UMd

use

UF1

U Tasmania

UC Berkeley

UMass

USGS

Boise State

UC Davis

UC Berkeley

WHOI

USGS

U Miami

U SCarolina

USGS

UC Santa Cruz

Lab. Glac. d Geophy. Envir.

Rutgers

U Montpellier

USGS

CSU Hayward

79